SCHOOL OF ENGINEERING

P01 –

Treasures at data centre

E223 : IT FOR SUPPLY CHAIN MANAGEMENT

Copyright © 2009 School of Engineering, Republic Polytechnic, Singapore

All rights reserved. No part of this document may be reproduced, stored in a retrieval

system, or transmitted, in any form or by any means, electronic, mechanical,

photocopying, recording or otherwise, without the prior permission of the School of

Engineering, Republic Polytechnic, Singapore.

Treasures at data centre

Server and racks

Air-conditioner at 25 ˚C

PC for scrap

A*N Logistics has been a transportation carrier company that make extensive use of IT for its operations. While IT has provided the company a competitive advantage over its competitors, it also poses another challenge to the IT department to come up with a strategy to make the data more secure and at the same time having minimal downtime. Currently, the data and files in A*N Logistics are stored in a few servers which reside in a simple server rack. A small unused room in the office was used to store the rack. An air-conditioner, calibrated at 25 degree Celsius was used to cool the servers 24 hours a day throughout the year. The room is accessible by any staffs working in the company. Other than that, there was no special setup at the “server room”. Besides that, the “server room” is also used to store scrapped or faulty items such as PCs, printers and mouse temporarily and it is quite crammed. The servers contain databases, applications, emails and data files that company requires for its logistical operations. In the event that a server is down, a backup server will be setup to replace the non-functional one. When such event occurs, it may take more than a day’s effort to restore and all logistical planning would done manually.

In order to ensure customer service level is met, what could you propose to the company so that it could improve and ensure service continuity?

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P01

Treasures at Data Centre

E223 – IT for Supply Chain Management

Regulation,

Governance

Control

Data Centre Information Technologies

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Classification of Information Technologies

Computer hardware technologies: including microcomputers, midsizeservers, and large mainframe systems, and the input, output, and storagedevices that support them.

Computer software technologies: including operating system software, Webbrowsers, software productivity suites, software drivers, databasemanagement systems, software for business applications like customerrelationship management and supply chain management, and other software-based components and modules.

Telecommunications network technologies: including thetelecommunications media, processors, and software needed to provide wire-based and wireless access and support for the Internet and private Internet-based networks such as intranets and extranets.

Data resource management technologies: including database managementsystem software for the development, access, and maintenance of thedatabases of an organization.

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Hardware Technologies

All hardware falls into one of the following categories: Input device—tool you use to enter information and commands. E.g.

keyboard, mouse, touch screen, game controller, and bar code reader. Output device—tool you use to see, hear, or recognize the results of your

information-processing requests.E.g. printer, monitor, and set of speakers.

Storage device—tool you use to store information for use at a later time.E.g. hard disk, flash memory card, and DVD.

Central processing unit (CPU)—the hardware that interprets and executesthe system and application software instructions and coordinates theoperation of all the hardware. E.g. Intel Pentium and Xeon.

Memory—RAM is a temporary holding area for the information you’reworking with as well as the system and application software instructionsthat the CPU currently needs.

Connecting device—includes such things as a USB port into which youwould connect a printer

Hard disk RAM CPU USB cable

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Software Technologies There are two main types of software: Application and System

Application software is the software that enables you to solve specificproblems or perform specific tasks. E.g. Microsoft Word, payroll software,collaborative software, and inventory management software

System software handles tasks specific to technology management andcoordinates the interaction of all technology devices. Within systemsoftware, you’ll find operating system software and utility software. Operating system software is system software that controls your

application software and manages how your hardware devices worktogether. Popular operating systems include Microsoft Windows (andall its variations), Mac OS, Linux (an open-source operating system),and Unix.

Utility software is software that provides additional functionality toyour operating. Utility software includes anti-virus software, screensavers, uninstaller software, file security software (which usuallyincludes encryption), and a host of others.

Systems Software:

Operating

Systems

Utility Software:

Antivirus

Application Software:

Warehouse

Management System

Application Software:

Microsoft

Word

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Telecommunications network technologies

It consists of communications media, communications processors, networkaccess and control software

Communications media – tools that enables connection over the network(l E.g. Network Interface Card – NIC –wireless/wired) or to interconnectworkstations and computer peripherals (E.g. telephone line, coaxial cable,wireless, blue-tooth, infrared)

Telecommunications device—tools that you use to send information toand receive it from another person or computer in a network.E.g. Modem

Telecommunications control software – programs that controltelecommunications activities and manage telecommunications networks.E.g. Network traffic monitoring program, User management and networkaccess control program

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NIC Modem Network

Traffic

Monitoring

Program

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Data resource management technologies

Data resource management is a critical management activity. Managementroles include database administration, data planning, and data administration.

Under the database management approach, data records are consolidatedinto databases that can be accessed by many different application programs,serving multiple users.

Several types of databases are used by the company re such as end-userdatabases, external databases on internet or online service, operationaldatabase of a company, data warehouse.

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Databases

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Types of Computer software

(Detail Classification)

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Software Alternatives

Outsourcing Many businesses are finding alternatives to acquiring, installing, and

maintaining business application software purchased from softwarevendors or developing and maintaining their own software in-house withtheir own software developer employees. E.g. many large companies areoutsourcing the development and maintenance of software they need tocontract programming firms and other software development companies,including the use of offshore software developers in foreign countries, andusing the Internet to communicate, collaborate, and manage theirsoftware development projects.

ASP A large and fast-growing number of companies are turning to application

service providers (ASPs), instead of developing or to run their businesses.Application service providers are companies that own, operate, andmaintain application software and the computer system resources(servers, system software, networks, and IT personnel) required to offerthe use of the application software for a fee as a service over the Internet.The ASP can bill their customers on a per-use basis, or on a monthly orannual fee basis.

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Data centre physical access restrictions

Door controls – Data centre doors must be equipped with a sturdy lock orcard access system. Only the handful of people who have access to the serverenvironment have the access. The card reader can track and log who entersand leaves a Data Centre.

Closed-Circuit Television Coverage – This provide a real-time surveillance ofwho enters the server environment. The camera is typically monitored bycompany security personnel.

Access Policies and Procedures – Establish a data centre policy that defineswho is allowed to enter the room and under what circumstances.

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Card Access Closed-Circuit

Television Coverage

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Data centre environmental control and

protection systems (Cooling) Data Centre must cool the networking devices, and other machines that it

houses. The environmental control in a building that regulate temperatures andair circulation are referred to collectively as HVAC— heating, ventilation, andair conditioning. This HVAC infrastructure has three jobs to do in a Data Centre:

Keep temperatures low (between 18.3 and 23.9° Celsius)

Keep them constant

Diffuse hot spots created by clusters of equipment

Low temperatures are necessary for the efficient operation of servers. Theyfunction more effectively at cooler temperatures—due to lower electricalresistance of circuits and heat removal is more efficient. Metal rust slower whenkept in cold environment instead of warm ones.

Constant temperatures are required in server environments becausefluctuations are hard on servers and network devices.

Diffusing hot spots is necessary to prevent the exhaust from one cluster ofservers from adversely affecting other nearby devices.

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Cooling process, airflow and under floor

routing

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Server Racks

Under floor

routing and

termination of

cables

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Data centre environmental control and

protection systems (Fire suppression) A Data Centre is just as vulnerable to fire as any other conventional office

building space Computer hardware can potentially short circuit, for example. orflames might start in another part of the building and then spread to the serverenvironment. Whatever the cause, comprehensive fire suppression system mustbe installed. The following are some implementation:

Suppression Materials - Gaseous suppressant is most commonly used in serverenvironments because it does not harm servers or leave a large mess behindafter discharging. E.g. Inert gas: Argonite (Argon – 50% + Nitrogen – 50%)

Sprinklers - Install a dry system into your server environment. This reduces therisk of water being accidentally spilled into the room if the pipe is damaged.

Air sampling and smoke detection – 2 types: smoke detection system thatcontinuously sample the air or one that detects heat from fire and discharge theextinguishing materials.

Fire alarms

Handheld extinguishers

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Fire alarms

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Monitoring Devices Web Cameras

A great way to tell what’s happening in your Data Centre is to deploy webcameras that leverage the room’s network. Connect them to a port on theData Centre’s existing networking equipment and transmit the live imagesacross your internal network.

AmperageMeters

An additional method of keeping an eye on the Data Centre is having yourserver cabinet power strips equipped with amperage meters. These devicesdisplay the amount electrical load that is put upon them. This tells a DataCentre user how close they are to reaching the maximum electrical capacity ofa power strip.

Temperature Sensors

Yet another useful thing to know about your Data Centre is how hot or cold itis. Monitoring the temperature of the room can alert you to a malfunctioningair handler, air flow problems. or hot spots that are forming due to increasedserver density at a particular cabinet location.

Humidity Sensors – Same device as devices that take ambient temperaturereadings.

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Availability Metric Availability Metric measures the degree in which the data centre is on line.

Availability metrics can also justify the expense of additional Data Centreinfrastructure, either when designing a new room or when upgrading anexisting one.

Outages refers to the cumulative number of minutes the data centre wasoffline during the defined period of time. By keeping track of the lengths ofoutages throughout the year, you can calculate availability for any timeperiod—monthly, quarterly, or annually.

Percentage of availability = (Time – Outage) /Time

E.g. A*N data centre was offline for 60 minutes over the course of a 30-daymonth. There are 43,200 minutes in that month (30 days x 24 hours in a day x60 minutes in an hour = 43,200 minutes).

Being online for all but 60 minutes translates to 99.86 percent availability:

(43,200—60) ÷ 43,200 = 99.86 percent availability

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Downtime

Outage expenses can range from lost potential revenue to a damagedreputation with customers and in the marketplace. The cost of downtimevaries from industry to industry. For some, even an hour or two can bedevastating.

Downtime can be classified into three different areas:

Mission critical-If the application is down, then critical business processesand/ or customers are affected in a way that has massive impact on thecompany’s profitability

Business Critical-Downtime that is often not visible to customers, but doeshave a significant cost associated with it

Task Critical-The outage affects only a few users, or the impact is limitedand the cost is insignificant.

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Regulation and governance

Examples of organizations and their regulations in Singapore IDA – Info-communications, Telecoms, Postal Services, Electronic Transactions

AVA – Food, Animals and Pets, Agriculture and Fisheries

LTA – Building works and Restricted activities in railway, Street proposals, VehicleParking

ACRA – Accounting and Corporate regulatory, Accountants, Business registration,Companies, LLP

IT control measures of Sarbanes-Oxley Act (SOX) of 2002 in US IT security

Change control

Data Management

IT Operations

Network operations

Asset Management

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IT Governance

What is IT governance?

The overall objective of IT governance is to understand the issues andstrategic importance of IT so the enterprise can sustain its operations andimplement the strategies required to extend its activities into the future.IT governance aims to ensure that expectations for IT are met and IT risksare mitigated. IT governance is the responsibility of the board of directorsand executive management. It is an integral part of enterprise governanceand consists of the leadership and organizational structures and processesthat ensure that the organization’s IT sustains and extends theorganization’s strategies and objectives.

At the heart of the governance responsibilities of setting strategy,managing risks, delivering value and measuring performance are thestakeholder values, which drive the enterprise and IT strategy. Sustainingthe current business and growing into new business models certainly arestakeholder expectations, and can be achieved only with adequategovernance of the enterprise’s IT infrastructure.

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Motivation and Importance

Motivation for IT governance:

Organizations today are subject to many regulations governing dataretention, confidential information, financial accountability and recoveryfrom disasters. IT governance ensures internal controls.

The purpose of IT governance is to ensure that IT’s performance meets thefollowing objectives:

Alignment of IT with the enterprise and realization of the promisedbenefits

Use of IT to enable the enterprise by exploiting opportunities andmaximizing benefits

Responsible use of IT resources

Appropriate management of IT-related risks

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Major IT Management Frameworks –

ITIL, CMMI, COBIT ITIL: The Information Technology Infrastructure Library (ITIL) provides a

framework of best practice guidance for IT Service Management (ITSM) that hasbecome the most widely used and accepted approach to IT service managementin the world. ITIL is a good fit for organizations concerned about operations.

CMMI: The Capability Maturity Model Integration (CMMI) method, created by agroup from government, industry and Carnegie-Mellon’s Software EngineeringInstitute, is a process improvement approach that contains 22 process areas. It isdivided into appraisal, evaluation and structure. CMMI is particularly well-suitedto organizations that need help with application development, lifecycle issuesand improving the delivery of products throughout the lifecycle.

COBIT: This framework, from the Information Systems Audit and ControlAssociation (ISACA), is probably the most popular. Basically, it’s a set of guidelinesand supporting toolset for IT governance that is accepted worldwide.

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Problem Statement Solution

From the view of IT governance and policy, which would ensure processcompliance and information integrity, suitable IT framework may be adopted.For data centre, ITIL may be used. Combining frameworks can also makesense. You might want to use CoBIT as an overall framework; then use ITIL forthe operations, CMMI for development and ISO 17799 for security.

The company should consider setting up a data centre which has physicalrestriction in place, so that only authorized personnel can access the facilityusing access card. There should also be environmental control and protectionsystem for cooling and such as HVAC— heating, ventilation, and airconditioning and for fire suppression. They should also install monitoringdevices. Availability metrics are important for monitoring and improving theavailability of the data centre. By doing this, it would enable the company toensure customer service level is met. To improve and ensure servicecontinuity, an on site data centre is needed for normal operation which wouldensure minimal downtime when the server is down. An offsite data centre isneeded for disaster recovery.

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Problem Statement

The equipment and software required for Data centre can be classified intofour categories of information technologies: computer hardwaretechnologies, computer software technologies, network technologies anddata resource management technologies.

For software, it can be outsourced instead of developed in-house. Applicationservice provider can also be used.

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Learning Outcomes

Classify information technologies into computer hardware technologies,

computer software technologies, network technologies and data

resource management technologies

Explain the importance and features of data centre environmental

control and protection systems (Cooling, fire suppression) , monitoring

(web cameras, temperature/humidity sensors), physical access

restrictions and metrics (availability metrics)

Explain the need for IT governance and policy to ensure process

compliance and information integrity.

SCHOOL OF ENGINEERING

P02 – Information systems

and development

E223 : IT FOR SUPPLY CHAIN MANAGEMENT

Copyright © 2009 School of Engineering, Republic Polytechnic, Singapore

All rights reserved. No part of this document may be reproduced, stored in a retrieval

system, or transmitted, in any form or by any means, electronic, mechanical,

photocopying, recording or otherwise, without the prior permission of the School of

Engineering, Republic Polytechnic, Singapore.

Information systems and development Vista Logistics wants to upgrade its current application systems so that it is able to provide value added services to its customer and better competes with its competitors. It also wanted to improve its internal administrative and operation activities. The following are three types of systems identified and the budget is allocated for FY09/10:

Item Systems/Software needed Description

1 Asset Management System To keep track of the loan items by the staffs

2 Warehouse Management System

To manage the warehouse activities more effectively

3 GPS tracking software To track the trucks and ensure the visibility

Currently the company has an IT department with staff strength of six (comprising: 1 IT manager, 2 systems analysts, 2 network engineers and 1 database analyst). Advise the manager whether he should develop the systems in-house or he should look for other source of software. If the systems were to be developed in-house, what systems development methodology would you recommend to him?

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P02

Information systems and

development

E223 – IT for Supply Chain Management

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A system A system is an interrelated set of business procedures (or

components) used within one business unit, working together forsome purpose. E.g. an inventory system keep track of supplies.

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constraints

Interrelated components

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Nine characteristics of a system Components – It is either an irreducible part or an aggregate of parts,

also called subsystems.

Interrelated Components – Components are interrelated, i.e. thefunction of one is tied to the functions of the others.

Boundary – It establish the limit of a system, e.g. to sort by receipt date

Purpose – All the components work together to achieve some overallpurpose for the larger system.

Environment – The system exists within an environment e.g. awarehouse environment

Interfaces – A system interacts with its environment. The points thesystem meets its environment are called interfaces.

Constraints – The system must face constraints – the limits e.g. speed,capacity to what it can do and how it can achieve its purpose within theenvironment.

Input – A system takes input from its environment in order for it tofunction.

Output – A system returns output to its environment as a result of itsfunctioning and thus achieve its purpose.

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Information Systems

Information Systems

All the components and resources necessary to deliver information and functions to the organization

Could be paper based

Types of Information Systems:

Operations Support Systems

Efficiently process business transactions

Control industrial processes

Support communication and collaboration

Update corporate databases

Management Support Systems

Provide information as reports and displays

Give direct computer support to managers during decision-making

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Classification of Information Systems

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Sources of software application

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Sources of software application

Criteria for choosing

off-the-shelf

Software

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Sources of software applicationProducers When to use Internal Staffing Requirement

IT Services firm When task requires custom support

and system can’t be built internally

or system needs to be sourced

Internal staff may be needed,

depending on application

Packaged Software Producers When supported task is generic Some IS and user staff to define

requirements and evaluate

packages

Enterprise Solutions Vendors For complete systems that cross

functional boundaries

Some internal staff necessary but

mostly need consultants

Application Service Providers

and/or Managed Service

Provider

For instant access to an application

when supported task is generic (ASP

only)

Few; both ASP and MSP free up

staff for other IT work

Open Source Software When supported task is generic but

cost is an issue

Some IS and user staff to define

requirements and evaluate

packages

In-house developers When resources and staff are

available and system must be built

from scratch

Internal staff necessary though

staff size may vary

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Systems Development Life Cycle

(SDLC) System Development Methodology

Standard process followed in an organization

Consists of:

Analysis

Design

Implementation

Maintenance

Series of steps used to manage the phases of development for aninformation system. Consists of four phases:

Planning and Selection

Analysis

Design

Implementation and Operation

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Phases of SDLC 1. Systems Planning and Selection

Two Main Activities

Identification of need

Investigation and determination of scope

2. Systems Analysis

Study of current procedures and information systems

Determine requirements

Generate alternative designs

Compare alternatives

Recommend best alternative

3. System Design

Logical Design

Concentrates on business aspects of the system

Physical Design

Technical specifications

4. System Implementation and Operation

Implementation

Hardware and softwareinstallation

Programming

User Training

Documentation

System changed to reflectchanging conditions

System obsolescence

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The Waterfall Model The waterfall model was one of the

earliest models to be designed. It has a

natural timeline where tasks are executed

in a sequential fashion.

At the top of the waterfall, a feasibility

study flow down through the various

project tasks finishing with

implementation into the live environment.

Testing tends to happen towards the end

of the project life cycle so defects are

detected close to the live implementation

date.

It has been difficult to get feedback

passed backwards up the waterfall and

there are difficulties if we need to carry

out numerous iterations for a particular

phase.

This model assumes that requirements

will remain stable after they are

defined

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V-Model The V-Shaped life cycle is a sequential path of execution of processes. Each

phase must be completed before the next phase begins. Testing isemphasized in this model. The testing procedures are developed early in thelife cycle before any coding is done, during each of the phases precedingimplementation.

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V-Model – 4 Test Levels A common type of V-model uses four test levels. The four test levels used,

each with their own objectives:

Component testing - searches for defects in and verifies the functioning ofsoftware components (e.g. modules, programs, objects, classes etc.) that areseparately testable

Integration testing - tests interfaces between components, interactions todifferent parts of a system such as an operating system, file system andhardware or interfaces between systems

System testing - concerned with the behavior of the whole system/product asdefined by the scope of a development project or product. The main focus ofsystem testing is verification against specified requirements

Acceptance testing - validation testing with respect to user needs,requirements, and business processes conducted to determine whether ornot to accept the system.

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Iterative Development Model

Delivery is divided into increments or builds with each increment adding new

functionality. The initial increment will contain the infrastructure required to support the

initial build functionality. The increment produced by an iteration may be tested at several

levels as part of its development. Subsequent increments will need testing for the new

functionality, regression testing of the existing functionality, and integration testing of both

new and existing parts.

Regression testing is increasingly important on all iterations after the first one. This

means that more testing will be required at each subsequent delivery phase which must

be allowed for in the project plans. This life cycle can give early market presence with

critical functionality, can be simpler to manage because the workload is divided into

smaller pieces, and can reduce initial investment although it may cost more in the long

run. Also early market presence will mean validation testing is carried out at each

increment, thereby giving early feedback on the business value and fitness- for-use of the

product.

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Test

Test

Test

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Alternative approaches -Prototyping

The analyst works with users todetermine the initial or basicrequirements for the system. Theanalyst then quickly builds aprototype.

When the prototype is completed,the users work with it and tell theanalyst what they like and do notlike about it.

The analyst then uses this feedbackto improve the prototype and takesnew version back to the users. Thisiterative process continues untilthe users are relatively satisfiedwith what they have seen

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Alternative approaches –Prototyping Most useful when:

User requests are not clear

Few users are involved in the system

Designs are complex and require concrete form to evaluate fully

History of communication problems between analysts and users

Tools are readily available to build prototype

Drawbacks

Tendency to avoid formal documentation

Difficult to adapt to more general user audience

Sharing data with other systems is often not considered

Systems Development Life Cycle (SDLC) checks are often bypassed

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Alternative approaches - RAD (Rapid

Application Development) Model

Components/functions are developed in parallel as if they were mini projects, the

developments are time-boxed, delivered, and then assembled into a working

prototype. The RAD development process encourages active customer feedback. The

customer gets early visibility of the product, can provide feedback on the design and

can decide, based on the existing functionality, whether to proceed with the

development, what functionality to include in the next delivery cycle or even to halt the

project if it is not delivering the expected value. An early business-focused solution in

the market place gives an early return on investment (ROI) and can provide valuable

marketing information for the business. Validation with the RAD development process

is thus an early and major activity,

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Alternative approaches - Joint

Application Design (JAD) Participants

Session leader

Users

Managers

Sponsor

Systems analysts

Scribe

IS staff

End Result

Documentation detailing existing system

Features of a replacement system

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Problem Statement

A system has nine characteristics. In general, information system may beclassified into management support system and operations supportsystem.

It is not always necessary to develop all the required system from scratch.There are six sources of software application and a company shouldcarefully evaluate the approaches to use with respect to the number ofinternal IT staffs in the company.

A systems development lifecycle consists of four phases. There are variousapproaches to software development and the company should chooseone that best fits its needs.

Water fall model may be costly as it does not provide opportunity forfeedback. In this aspect, the iterative development model might haveresolved the issue by performing the software development in phases. Ifthe company focuses more on testing, it may want to adopt V modelinstead.

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Problem Statement For alternative approaches, prototyping may be good when user

requirement are not so clear and need to evaluate fully. However, theremust be tool for prototype development.

For RAD, the benefit is that it decreases the time needed to design andimplement information system. It delays producing detailed systemdesign documents until after user requirements are clear. It may be fastbut it sacrifices computer efficiency for human efficiency in rapidlybuilding and rebuilding working systems. It may also overlook importantsystems development principles.

JAD is a structured process in which the users, managers and analystswork together for several days in a series of intensive meetings to specifyor review system requirements. One good thing about this approach isthat systems requirement are properly documented.

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Learning Outcomes

Describe the characteristics of a system and classification of

information system

Describe different sources of software application

Illustrate different software development models and alternative

approaches to development

SCHOOL OF ENGINEERING

P03 – Model the business data!

E223 : IT FOR SUPPLY CHAIN MANAGEMENT

Copyright © 2009 School of Engineering, Republic Polytechnic, Singapore

All rights reserved. No part of this document may be reproduced, stored in a retrieval

system, or transmitted, in any form or by any means, electronic, mechanical,

photocopying, recording or otherwise, without the prior permission of the School of

Engineering, Republic Polytechnic, Singapore.

Model the business data! Renheng Logistics is a logistics company that makes extensive use of information technology. Within the company, it has a large resource centre that has many essential items for daily operations and the staffs have to check out the required items each day. When each staff borrows an item from the resource centre, he or she has to scan the staff pass and the data would be captured and stored in an Excel spreadsheet. As the resource centre operations manager, Bak Seng uses separate Excel spreadsheets to record daily loan details. This includes the employee loans, the vendor deliveries and employee information. During monthly management meeting, he has to collate all the daily transaction data and analyze the monthly loan statistics. This process is tedious, erroneous and manual. With the increase in business, the number of transactions increases and the current way of storing and accessing data makes it somewhat inefficient and error-prone. A Database Management System (DBMS) is proposed and the initial step is to model the existing operations information to be stored in the database. Describe how he should take the initial step and present his idea to the management.

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P03

Model the business data!

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E223 – IT for Supply Chain Management

Business Data Model

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Problems in Storing and Accessing

Data Volume or amount of data

Data security

Data privacy

Backup and recovery

Maintaining the accuracy

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The database environment

The database environment is designed to largely correct all the

problems of the non database environment.

It encourages data sharing and the control of data

redundancy, with important improvements in data accuracy.

It permits the storage of vast volumes of data with acceptable

access and response times for database queries.

It provides the tools to control data security, data privacy, and

backup and recovery.

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Data Modeling Data modeling is a process whereby the relationships between

data elements are identified and defined.

Entity Relationship Diagrams (ERDs) have three basic elements: entity types, relationships, and attributes.

An entity type is a collection of entities (persons, places, events, or things) of interest

A relationship represents a two-way or bidirectional association among entities.

An attribute is a property of an entity type or relationship and each attribute has a data type.

The result of data modeling is an ERD that represent the requirements

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Data modeling Tool and NotationData Modeling Tool:

MySQL Workbench

Crow’s Foot Notation for entity

and relationship

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Relationships

Entity

Text

Relationship

cardinalities specify

how many of each

entity type is allowed

Relationship degrees specify

number of entity types involved

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Type of relationship –

1-to-1 binary relationship

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One-to-one (1-1) binary relationship

An employee is assigned to at most one parking space in a particular

car park.

Conversely a particular parking space has one employee assigned to it.

Is_assigned

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Type of relationship –

1-to-Many binary relationship

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One-to-Many (1-M) binary relationship

An employee has many loans.

Conversely, each loan is placed by exactly one employee.

LoanType describe the type of loan e.g. short-term/long-term

loans

Is loaned by

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Type of relationship –

Many-to-Many binary relationship

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Many-to-Many (M-M) binary relationship

A loan transaction may have may items

An item may appear on multiple loan transactions

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Many-to-Many binary relationship with

Intersection Data

The intersection data describes the relationship between the

two entities. E.g. the LoanTransaction falls at the intersection of

Loan and Item.

Another way to call this is M-to-M relationships with attributes

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Intersection Data

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Type of relationship –

1-to-1 Unary relationship

Unary relationships associate occurrences of an entity type

with other occurrences of the same entity type. E.g. Employee id

099 backs up employee id 098.

Note that the 1-1 relationship forbids the situation whereby an

employee has no backup

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Backup

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Type of relationship –

1-to-Many Unary relationship

E.g. Some of the employees are also managers, managing other

employees. A manager can manage several other employees.

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Manages

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Type of relationship –

Many-to-Many Unary relationshipX

S1

C1 C2

S2

C3

S3

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Y

S4

C4 C2

S5

S3 S7

S6

The above figures shows the Bill-of-materials (BOM) Structure for item X and item

Y. E.g. S3 is used in both items X and Y and at different levels of the BOM. The

many-to-many relationship guarantees that the same subassembly structure of S3

is used each time S3 goes into making some other item.

Each basic item and each subassembly can be thought of as a “part” of the object.

Hence the item are in many-to-many relationship with each other. Any one

particular item can be made up of several other components, while being

components of several other products.

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Many-to-Many Unary relationship

Representation

13

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Ternary (M-Way) relationship

A ternary (M-Way) relationship involves three different entities types

(>2). In Crow’s Foot Notation, it is not possible to directly represent

such a relationship. Hence it should be represented in an “associative

entity type” (as represented by Supply) and a collection of 1-M

relationships (Vendor and Supply, Warehouse and Supply and

Product and Supply) to represent an M-way relationship.

14

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Problem statement – Final ERD

15

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Learning Outcomes

Discuss data modeling concept

Explain the entity relationship in business environment such as

Unary one-to-one, one-to-many, many-to-many relationship

Binary one-to-one, one-to-many, many-to-many relationship and intersection data

Ternary relationship

Model the data in business environment using Entity Relationship diagram (ERD)

16

SCHOOL OF ENGINEERING

P04 – From Model to Database Tables

E223 : IT FOR SUPPLY CHAIN MANAGEMENT

Copyright © 2009 School of Engineering, Republic Polytechnic, Singapore

All rights reserved. No part of this document may be reproduced, stored in a retrieval

system, or transmitted, in any form or by any means, electronic, mechanical,

photocopying, recording or otherwise, without the prior permission of the School of

Engineering, Republic Polytechnic, Singapore.

From Model to Database Tables Hock An works in the IT department of a famous Logistics MNC. Currently, the company has a resource centre that provides essential items for daily operations but the loan was recorded manually and it is quite inefficient. It is also tedious to do transaction checks. To improve the current process, he is tasked to create a database to manage all the data for the loan process. After a preliminary discussion with various parties in the company, Hock An understood the requirements and modelled the whole process into an Entity Relationship Diagram (ERD), ready for implementation in the company’s database.

Hock An needs to implement the above design into the database. How should he accomplish his task?

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P04From Model to Database Tables

E223 – IT for Supply Chain Management

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Relational Database - Table

A relational database consists of a collection of tables.

A table is a 2 dimensional arrangement of data. Each table

consists of a heading defining the table name and a column

names and a body containing rows of data

E.g. Course Table

Rows of data

Column Names

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Common Data Types Data types indicate the kind of data (character, numeric, Yes/No,

etc) and permissible operations (numeric, string) for the column.

Each data type has a name and a length specification

Common Data types

Data Type Description

CHAR (L) For fixed length text entries. E.g. state abbreviations, NRIC number

VARCHAR (L) For variable length text. E.g. names, street addresses, description

FLOAT (M,D) For floating precision numeric data. Accurate to 7 decimal places.

For double precision numeric data. Accurate to 15 decimal places.

For decimal numeric data.

M= maximum number of digits or precision, D=decimal points to the right

E .g. payment amount, weight, interest rate, scientific

DOUBLE (M, D)

DECIMAL (M,D)

DATETIME For date and time. E.g. order delivery time

INT For whole numbers/integer i.e. without decimal point

BOOLEAN For data with 2 values (0 and 1) such as 0 for False/No and 1 for True/Yes

BLOB For large binary object that hold a variable amount of data e.g. image file

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Primary key in a relation

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Candidate keyEmployee

NumberNRIC

NumberPassport

Number

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Foreign key

Primary

Key

Foreign

Key

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Composite Keys

In the Enrollment table, the combination of StdSSN and OfferNo

is the only candidate key. Both columns are needed to identify a

row.

A primary key consisting of more than one column is known as

a composite or a combined primary key.

Hence Primary Key = OfferNo + StdSSN

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Null Values

NULL is a special value that represents the absence of an actual

value. A null value can mean that the actual value is unknown or

does not apply to the given row.

The proper functioning of the database requires that primary

keys can never be null. The primary key for each entity must

always have a unique, valid value for each instance of the entity.

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Basic Conversion Rule

The basic conversion rules applies except generalization hierarchies

Rule Description

R1 Entity Type

Rule

Each entity type becomes a table. The primary key of the entity

type becomes primary key of the table. The attribute type becomes

columns of the table. This rule should be used before

relationship rule.

R2 1-M

Relationship

Rule

Each 1-M relationship becomes a foreign key in the table

corresponding to the child entity type. If the minimum cardinality on

the parent side of cardinality is 1, the foreign key cannot accept

null values.

R3 M-N

Relationship

Rule

Each M-N table becomes a separate table. The primary key of the

table is a combined key consisting of the primary key of the entity

types participating in the M-N relationship.

R4 Identification

Dependency

Rule (Weak

Entity)

Each identifying relationship adds a component to a primary key.

The primary key of the corresponding weak entity consists of (local

key in weak entity + primary key of the connected entity)

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Mapping a regular entity

10

SupplierId SupplierName SupplierAddress ZipCode

Using rule R1, Each entity type becomes a table.

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Converting Entities in 1-to-1 Binary

Relationship The conversion is done using R1 and R2 such that each employee is

assigned a parking space.

PK of ParkingSpace

PK of Employee FK of ParkingSpace

Employeeid EmployeeName DepartmentName Salary LotNumber

LotNumber Carpark

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Converting Entities in 1-to-M Binary

Relationship The conversion is done using R1 and R2. One employee may have

multiple loans. So the EmployeeId attribute is placed in the Loan table

as a foreign key.

PK of Employee

FK of EmployeePK of Loan

LoanId LoanType Employee_EmployeeId

EmployeeId

EmployeeName

DepartmentName

…

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Converting Entities in M-to-N Binary

Relationship Using R1 and R3, each of the two entities: Item and Loan converts to a

table with its own attributes but with no foreign keys (regarding this

relationship). There is a separate table: LineItem, for the many-to-many

relationship. The primary key of this additional table is the combination

of the unique identifiers of the two entities in the many-to-many

relationship.

Composite Key = PK of Item + PK of Loan

ItemId ItemDescription …. ItemQuantity

LoanId LoanType Employee_EmployeeId

Item_ItemId Loan_LoanId ….

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Converting Entities in 1-to-1 unary

relationship Using R1 and R2, with only one entity type involved and with a one-to-

one relationship, the conversion requires only one table.

E.g. for a particular employee, the Backup Number attribute represents

the employee number of his backup person—that is, the person who

covers his work when he is away for any reason.

PK of Employee

Employeeid EmployeeName DepartmentName Salary Employee_Employeeid

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Converting Entities in 1-to-Many unary

relationship Using R1 and R2 for conversion, the one-to-many unary relationship

situation is very similar to the one-to-one unary case.

E.g. In this case, some employees manage other employees. Anemployee’s manager is recorded in the Manager Number attribute in thetable. The manager numbers are actually salesperson numbers because,some salespersons are sales managers who manage other sales- persons.

This arrangement works because each employee has only one manager.

PK of Employee

EmployeeId EmployeeName DepartmentName Salary ManagerId

FK of Employee

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Converting Entities in a Ternary

relationship

ItemId CentreId SupplierId UnitCost SupplyQuantity

Composite Key make up of these

ItemId ItemDescription …. ItemQuantity

CentreId CentreName ZipCode

SupplierId SupplierName …. ZipCode

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Concluding remarks for ERD Conversion

In the conversion of a many-to-many relationship of any degree

(unary, binary, or ternary) – the number of tables will be equal to

the number of entity types (1, 2, 3, respectively) plus one more

table for the many-to-many relationship.

Conversion of M-N unary relationship: 2 tables

Conversion of M-N binary relationship: 3 tables

Conversion of M-N ternary relationship: 4 tables

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Create a table using a Table Editor

18

Step 1: Enter the entity name in the table name field

Step 2: Enter the attributes in the column name field

and datatype in the datatype field

Step 3: Click on the Apply Changes button to execute the changes

Table created

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Create a table with foreign key

19

Step 1: Enter the entity name in the table name field

Step 2: Enter the attributes in the column name field

and datatype in the datatype field

Step 3: Enter the foreign key name

Step 4: Enter the foreign key

column and reference column in

another table

Table created

With foreign

keys

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Create a table for relationship with

composite key

20

Ensure the tables participating in the relationship are created.

Enter the entity name in the table name field

Create the composite primary key

Create the composite foreign key

Create a table

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Create a table for relationship with

composite key (primary key)

21

Step 1: Ensure the tables participating in the relationship are created.

Step 2: Enter the entity name in the table name field

Step 3: Enter the attributes in the column

name field and datatype in the datatype field

Create a table

Step 4: Click on the column

name and click on “+” to add the

primary key

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Create a table for relationship with

composite key(foreign key)

22

Step 1: Ensure the tables participating in the relationship are created.

Step 2: Enter the entity name in the table name field

Step 3: Enter the attributes in the column

name field and datatype in the datatype field

Create a table

Step 4: Enter the

foreign key name

Step 5: Enter the foreign key

column and reference column in

another table (for all the tables)

Table created

For relationship

With composite

key

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Create a table using script

23

Create an employee table with

primary key

Method 2:Type directly on the

Script tab

Note: Run the script by

pressing the execute

button and the tables

would be created.

If there is error, check the

syntax

Method 1: You can load a script from a text file

(.txt) created with a notepad/text editor onto

the script tab

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Problem Statement

Logical database design is the process of deciding how to arrange theattributes of the entities in the business environment into databasestructures such as the table of a database.

The goal is to create well-structured tables that properly reflect thecompany’s business environment.

Transformation of E-R diagram to database tables requires the rightdata type to be specified.

By making use of the conversion rule, the E-R diagram can beconverted to the respective tables to be implemented in a database.

A table in the database can be created using a table editor or createtable script.

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Learning Outcomes

Explain relational database and common data types

Categorize the major types of keys including primary, candidate,

foreign and composite keys

Discuss how various relationships are implemented in a

relational database using conversion rules

SCHOOL OF ENGINEERING

P05 – How do I extract useful

information?

E223 : IT FOR SUPPLY CHAIN MANAGEMENT

Copyright © 2009 School of Engineering, Republic Polytechnic, Singapore

All rights reserved. No part of this document may be reproduced, stored in a retrieval

system, or transmitted, in any form or by any means, electronic, mechanical,

photocopying, recording or otherwise, without the prior permission of the School of

Engineering, Republic Polytechnic, Singapore.

How do I extract useful information? After the new database design for asset management system was approved by the management, database tables were implemented in a production database in Ren Hao Logistics. It was used by the IT resource centre without any glitches since the beginning of the year. Year end has come and the management wanted to extract some information from the database for the coming annual meeting. From the initial meeting with Henry Leong, VP Logistics, you have gathered requirements about the request such as the information of the staff in the logistics department, what they have borrowed and what items are not available for staff loan. The information regarding the salary must also be sorted in descending order. In addition, the management also wants to find out which staff is eligible for overtime pay i.e. the salary must be less than $1600. The IT department has given you some database scripts so that you can create the necessary tables and populate the tables with the required data from the production database. Examine the request, propose the steps needed and come up with the required information.

Information:

Name, Department,

Salary, Item,

Loan, total spending

for each supplier?

Items available for

loan? Overtime

eligbility?

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P05

How do I extract useful

information?

E223 – IT for Supply Chain Management

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SQL statements

SQL was designed as a language for database definition,

manipulation, and control. The following table shows a quick

summary of the important SQL statements.

Statement Type Statement Purpose

Database Definition

Language

(DDL)

Create Schema, Table,

View, Alter Table

Physical design/maintenance:

Define new database, table,

view. Modify table definition

Database

Manipulation

Language

(DML)

Select, Update, Delete,

Insert

Implementation: Retrieve

content of tables, Modify,

remove, add rows

Database Control

Language

(DCL)

Commit, Rollback, Grant,

Revoke

Implementation/Maintenance:

Complete, remove transaction,

Add or Remove access rights

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SQL statement processing order Clauses of the SELECT statement:

SELECT

List the columns (and expressions) that should be returned from the query

FROM

Indicate the table(s) or view(s) from which data will be obtained

WHERE

Indicate the conditions under which a row will be included in the result

GROUP BY

Indicate categorization of results

HAVING

Indicate the conditions under which a category (group) will be included

ORDER BY

Sorts the result according to specified criteria

3

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SQL Expression and arithmetic

operators An SQL expression is a combination of constants, column names,

functions, and operators that produces a value.

For example, SELECT Price * Qty AS Amount renames the expression

Price * Qty to Amount in the result table to be queried

The followings are arithmetic operators used in SQL:

Operator Description

+ Addition: adds 2 numbers

- Subtraction: Subtracts one numeric from another

* Multiplication: Multiplies one number by another

/ Division: Divides one number by another

% Modulo: Calculates the integer remainder of a division

E.g. 25%5 = 0, 26%5=1, 27%5=2…. 30%5=0

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Filtering result using comparison and

logical operatorsComparison Operators

Operator Description

= Equals to

> Greater than

< Less than

<= Less than or equal to

>= Greater than or equal to

<> Not equal to

Logical Operators

5

Operator Description

AND Evaluates to true if both

expressions are true

OR Evaluates to true if either

expressions are true

BETWEEN Evaluates to true if within

a range

LIKE Evaluates to true if

matches a pattern

NOT Reverse a value

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SELECT statement with

i)comparison operator ii)logical operator SELECT *

FROM EMPLOYEE

WHERE SALARY<1600

SELECT *

FROM EMPLOYEE

WHERE SALARY BETWEEN 1000 AND 3000

Comparison operator

Logical operator

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Eliminate duplicates with DISTINCT

SELECT

EMPLOYEE_EMPLOYEEID

FROM LOAN

SELECT DISTINCT

EMPLOYEE_EMPLOYEEID

FROM LOAN

D

U

P

L

I

C

A

T

E

S

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Filtering data Using LIKE operator for inexact matches

SELECT * FROM ITEM

WHERE ITEMDESCRIPTION LIKE 'Mobile%'

Using IN operator to select rows based on multiple values for a

particular column

SELECT * FROM ITEM WHERE STATUSDESCRIPTION IN

('ORDERED','CHECKEDOUT')

8

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Sorting columns using ORDER BY in

table order SELECT * FROM LOANTRANSACTION

9

Table order, i.e. the order in

which the records are stored in the database

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Sorting columns using ORDER BY in

specific order SELECT * FROM LOANTRANSACTION

ORDER BY LOANDATETIME DESC

Sort the specialty

in descending order

Note: To sort in ascending

Order, simply change the

DESC to ASC

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Standard Aggregate Function

Aggregate

Function

Meaning and Comment

Count (*) Computes the number of rows.

Count

(Column)

Counts the non-null values in column; DISTINCT can be used to count the

unique column values

AVG Computes the average of a numeric column or expression excluding null

values; DISTINCT can be used to compute the average of unique column

values.

SUM Computes the sum of a numeric column or expression excluding null values;

DISTINCT can be used to compute the average of unique column values.

MIN Computes the smallest value. For string columns, the collating sequence is

used to compare strings.

MAX Computes the largest value. For string columns, the collating sequence is

used to compare strings.

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Combining Grouping with aggregate

function SELECT LOAN_LOANID, COUNT(*)

FROM LOANTRANSACTION

GROUP BY LOAN_LOANID;

12

Count the total number of

Item in each loan.

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Combining Grouping with aggregate

function and joining 2 tables SELECT E.EMPLOYEEID, E.EMPLOYEENAME, COUNT(*)

FROM EMPLOYEE E, LOAN L

WHERE E.EMPLOYEEID = L.EMPLOYEE_EMPLOYEEID

GROUP BY EMPLOYEEID;

13

Count the total

number of loans

per employee with

employee ID.

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What if grouping is done wrongly?

SELECT E.EMPLOYEEID, E.EMPLOYEENAME, COUNT(*)

FROM EMPLOYEE E, LOAN L

WHERE E.EMPLOYEEID = L.EMPLOYEE_EMPLOYEEID

GROUP BY EMPLOYEENAME;

14

There are two Ken Lim and they are grouped together and counted as 2. In

fact, there are should be two records with the employee name as “Ken Lim”.

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Using alias for column name

SELECT ZIPCODE AS 'POSTCODE' FROM SUPPLIER

15

Alias is an alternative

column or table name

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Exporting the data into a file

After formulating the queries, make use of the export function to

export each Result set into Excel Files so that they can be used

for data analysis

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Learning Outcomes

Interpret SQL statement and SQL expression

Illustrate using SQL SELECT statements with comparisonoperators and logical operators for filtering and ORDER BY forsorting

Illustrate using SELECT statements for joins and standardaggregate functions such as COUNT, AVG, SUM

Utilize GROUP BY, DISTINCT, LIKE, IN operator in SQLstatement

SCHOOL OF ENGINEERING

P06 – Simplify and Secure!

E223 : IT FOR SUPPLY CHAIN MANAGEMENT

Copyright © 2009 School of Engineering, Republic Polytechnic, Singapore

All rights reserved. No part of this document may be reproduced, stored in a retrieval

system, or transmitted, in any form or by any means, electronic, mechanical,

photocopying, recording or otherwise, without the prior permission of the School of

Engineering, Republic Polytechnic, Singapore.

Simplify and Secure! The logistics department of LK Pte Ltd uses MySQL database to manage the employee‟s loan transactions from the company. They report to the top management that this database really help them a lot in managing the data. The top management wants to benefit other departments by allowing them to access the same database and retrieve some data they need. But the HR department brings out a security issue, which is some of the confidential data should not be visible to all the departments e.g., the employee‟s salary information. Other departments also feel that it is troublesome if they need to write complicated SQL statements to retrieve data from multiple tables. What they want is a single customized “table” or “view” from which they can get all the information they need according to their requirements. After which they can use simple SQL statement to operate on this „table‟ or „view‟. On top of this, data access is also an issue when multiple departments start to use the database and many users complains of performance bottlenecks. Kumar, the manager of IT department, is tasked to look into these issues and come up with suitable solution and advises for the database users. Can you help him?

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P06

Simplify and Secure!

E223 – IT for Supply Chain Management

Grant, Revoke

SELECT, INSERT,

UPDATE, DELETE

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The motivation and objectives A SQL View is a virtual or derived table. Virtual means that a view

behaves like a base table but no physical table exists. A view can be

used in a query like a base table. However, the rows of a view do not exist

until they are derived from base tables.

3 objectives are achieved by using SQL view

Data independence reduce the impact of database definition changes on

applications that use a database. E.g. if a table name used in a view

changes, the view definition must be changed but applications using the

view do not have to be changed

Simplification of tasks. Many queries can be easier to formulate if a view

is used rather than base tables. Without a view, a SELECT statement may

involve many joins.

Security. Views provide a flexible level of security.

Restricting access by views is more flexible than restrictions for

columns and tables because a view is any derived part of a database.

Hence data not in the view are hidden from the user.

A view can also include aggregate calculations to restrict users to row

summaries rather than individual rows.

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Define a Single Table View

Basic Syntax for creating view:

CREATE VIEW name AS select

statement

E.g. Define a view named

EMPLOYEE_AIRCARGO for Air Cargo

department:

CREATE VIEW EMPLOYEE_AIRCARGO AS

SELECT EMPLOYEEID, EMPLOYEENAME,

DEPARTMENTNAME, SHIFT, DATEJOINED

FROM

EMPLOYEE WHERE

DEPARTMENTNAME =“AIR CARGO”

3

Data retrieved

using the view

View created:

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Define Multiple Table View

E.g. Define a view containing details of item purchased. Include

the item and supplier information in the View :

CREATE VIEW ITEM_PURCHASED AS

SELECT I.ITEMID, I.ITEMDESCRIPTION,

I.ITEMPICTURE,S.UNITCOST,

S.SUPPLIER_SUPPLIERID,

SR.SUPPLIERNAME,S.SUPPLYQUANTITY

FROM ITEM I, SUPPLIER SR, SUPPLY S

WHERE I.ITEMID=S.ITEM_ITEMID AND

SR.SUPPLIERID=S.SUPPLIER_SUPPLIERID

View created:

Data retrieved

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Using Views for Retrieval

E.g. Query Using a Grouping View:

To list all item purchased with the supplier’s name

In ascending order

SELECT *

FROM ITEM_PURCHASED

ORDER BY SUPPLIERNAME ASC

Data retrieved using the

ITEM_PURCHASED

view

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Creating View on Current Views

E.g. Define a view ITEM_TOTALCOST containing total item cost

based on the existing view ITEM_PURCHASED:

CREATE VIEW ITEM_TOTALCOST AS

SELECT ITEMID, ITEMDESCRIPTION,

SUPPLIERNAME,

(UNITCOST*SUPPLYQUANTITY) AS TOTAL_COST

FROM ITEM_PURCHASED

View created:

Data retrieved

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Using Views for Updates

An updatable view enables you to insert/update/delete rows in

the underlying base tables by performing the corresponding

operation on the view.

Rules for Single-Table Updatable Views

The view include the PK of the base table

All required fields (NOT NULL) of the base table without a

default value are in the view

The view’s query does not include GROUP BY or DISTINCT

keywords

If any rule is violated, the view is considered Read-Only.

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Original record in the EMPLOYEE_AIRCARGO view

Update record in the view

UPDATE EMPLOYEE_AIRCARGO SET SHIFT=“Morning”

WHERE EMPLOYEENAME =“Ahmad Bin Sharif”

And the record in the original table is updated:

8

Update Operation on Updatable View

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Database Security

– Authorization and Privilege

The GRANT statement is used to assign access privilege

E.g. GRANT SELECT ON ITEM_TOTALCOST TO APDUSER

The REVOKE statement is used to remove an access privilege

E.g. REVOKE SELECT ON ITEM_TOTALCOSTTO APDUSER

9

Privilege Explanation

SELECT Query the object

UPDATE Modify the value

INSERT Add a new row

DELETE Delete a row

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Performance Roadblocks

Improving database access includes effort to make it easier to

access the data and to improve performance using data

access. Time in all business environments is money and delay in

waiting for information have a real-world cost.

A bottleneck is anything that stands in the way of optimum

performance.

There are 3 major potential sources of performance bottlenecks:

Hardware platform: Database server and network

Database: Performance during data reads and writes directly

impacts application performance

Application: Poorly written inefficient application

Most hardware performance issues are caused by disk

performance, system memory or system processor. It can get

especially complicated because these are interrelated.

10

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Hardware performance

– Disk drive issues Disk drive issues - There are 2 ways to resolve hard disk

issues: upgrade the hardware or reduce the load. The best

solution is combination of both.

Installing more or faster hard disks can sometimes resolve the

problem, but at a cost.

3 ways to reduce the load:

Split the load between multiple hard disks

Increase more memory so that more data can be cached

Using a dedicated server. Meaning that MySQL is the only

server application running on the server.

11

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Hardware performance

– Memory issues Database use a lot of memory

and most DBMS would set aside

memory to cache data. When

there is a data read request, the

DBMS checks memory first before

going to the physical hard disk.

When data is written, it writes to

memory first until the hard disk

can be updated.

If memory becomes as issue, you

can either reduce the load on

system memory you can increase

the amount of memory installed in

the computer or reconfiguring the

computer as a dedicated server.

12

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Hardware performance

– Processor issues Every program and query that

runs puts an additional load on

the system processor. To

determine if the processor is the

bottleneck, look at the processor

free and busy time. The higher the

percentage of busy time, the greater

the load in the processor. When this

averages over 90 % of total time,

then processor performance is likely

a bottleneck.

The only ways to correct a

processor bottleneck are to reduce

the processor load, install a faster

processor, or install one or more

additional processors.

13

DB Server

CPU usage

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Database performance

One of the goals of data normalization is to improve write

performance by reducing the amount of data that must be written

during updates. However, normalization can impact read

performance because data retrieval often means having to join

multiple tables to get all of the data you need. In the real world,

you typically work toward a compromise between “perfect”

normalization and database read performance.

Database objects, especially indexes, also impact performance.

Indexes are used to sort and organize data. Well-designed

indexes help to optimize data read performance. The problem is

that each time you update the data in a table, the database

server must also update the data in all of the table indexes. The

more indexes you have, the more overhead required to keep

them updated.

14

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Problem Statement

Kumar should create views for different departments.

After the views are created, it should also grant authorized data

to the respective users in L.K Ptd Ltd. This can be accomplished

by setting the right privileges (SELECT, UPDATE, INSERT,

DELETE) to the users who can access the view.

On the aspect of data access performance issue, L.K Ptd Ltd

should examine whether it is a hardware issue (due to disk drive,

memory or processor) or a database issue (due to excessive

data normalization or poorly designed indexes).

After which appropriate measures can be taken to resolve it.

15

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Learning Outcomes

Explain and Illustrate using CREATE VIEW statements

and using VIEW for insert, retrieval, update, delete and

reporting

Devise VIEW authorization privileges

Explain the common performance bottlenecks (hardware

and database)

SCHOOL OF ENGINEERING

P07 – Where is my truck?

E223 : IT FOR SUPPLY CHAIN MANAGEMENT

Copyright © 2009 School of Engineering, Republic Polytechnic, Singapore

All rights reserved. No part of this document may be reproduced, stored in a retrieval

system, or transmitted, in any form or by any means, electronic, mechanical,

photocopying, recording or otherwise, without the prior permission of the School of

Engineering, Republic Polytechnic, Singapore.

Where is my truck?

PremierPack Logistics has recently implemented a Transport Management System (TMS) for use in its transportation fleet that ferried its goods to and fro its warehouses, the shipper’s premise and consignee’s premise. The warehouses are situated at Air Logistics Park (for air cargoes) and Mayen Logistics Park (for transshipment). The system was supposed to help in transportation planning, route planning and it should support multiple logons. However, there has been a surge in the number of incidents regarding the assignment of cargoes to the right trucks using TMS for delivery. This has affected the service level greatly as goods arrive late at the customers’ place due to unavailability of trucks. In some cases for export, the shippers also have to delay its production plan. You are given a special task by your assistant general manager to conduct a thorough investigation on database transactions and suggest measures to prevent any recurrence of existing problems. Mayan Logistics Park

[Trucks] [TMS] [Warehouse 1] [Seaport] Air Logistics Park

[Airport] [Warehouse 2] [TMS] [Trucks]

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P07

Where is my truck?

E223 – IT for Supply Chain Management

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Transaction Processing & Transaction

Transaction processing involves the operating side of databases

and it describes how “information goods” or transactions are

controlled.

In the context of databases, a transaction is a single unit of work

for the database. Transactions should be processed reliably so

that there is no loss of data due to multiple users or system

failures.

Potential problems encountered by critical database systems:

Concurrent transactions are transactions being processed

simultaneously by the database. The transactions can affect one

another adversely, producing incorrect and inconsistent results.

Hardware or software malfunction can result in data loss or

corruption.

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Transaction Properties

DBMSs ensure that transactions obey certain properties. The

most important and widely known are ACID properties:

Atomic means that a transaction cannot be sub-divided. Either all

the work in a transaction is completed or nothing is done

Consistent means that if applicable constraints are true before

transaction starts, the constraints will be true after the

transaction terminates

Isolated means transactions do not interfere with each other

except in allowable way. A transaction should not overwrite

changes made by another transaction

Durable means that any changes resulting from a transaction are

permanent. No failure will erase any changes after transaction

terminates.

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ACID Properties IllustrationScenarios Transaction

Properties

You wanted to withdraw $100 from an ATM. However, you entered wrongly

and keyed in $1000. Just before the ATM proceeds to deduct $1000 from your

account, you hit the Cancel button. The ATM aborts the transaction and

nothing was withdrawn. Your card was ejected.

Atomic

You have $5000 in an account. Suppose you withdraw $50 from it. The ATM

machine processes your request and check that the account balance shows

$4900 (which is not correct). The ATM automatically rejected the transaction

disallow your withdrawal. You still have $5000 in your account.

Consistent

You are withdrawing $100 from one ATM machine and you asked your friend

to deposit $50 that he owed you to the same account using a cash deposit

machine next to you. Initially you have $1000 and your friend has $800 in the

accounts respectively. Before you completed your withdrawal transaction or

before your friend has deposited the money, the initial balance that both of you

have seen is the same.

Isolation

There was a huge thunder and the ATM machine went blank for 60 seconds

while you are withdrawing money from the ATM machine. You left the ATM

machine and tried another machine to access your account. You checked that

your account balance and the money that you have withdrawn earlier still

tallied.

Durable

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Hotspot

Transaction executing simultaneously cannot interfere unless

they are manipulating common data. A hot spot is common

data that multiple users try to change simultaneously.

E.g. Suppose you have selected shipment X for transfer and your

colleague is also keen in reserving this shipment. Both of you are

trying to reserve at the same time.

Hotspot = shipment

E.g. Suppose you are booking a window seat near to the

emergency exit and your friends are also keen to have this seat.

Both of you are trying to reserve at the same time.

Hotspot = window seat near to the emergency exit

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Interference problems – Lost Update

Lost Update. In a lost update, one user’s update overwrites

another user’s update. The followings shows 2 concurrent

transactions trying to update the truck field for truck to be used

for shipment.

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The write

operation

performed by

A1 is not

known to A2

unless

Transaction

A2 reads the

value again

Final write

to DB

The

calculations

at times T3

and T4 are

performed in

memory

buffers

specific to

each

transaction

Transaction A1 Time Transaction A2

READ NT(1) T1

T2 READ NT(1)

If NT >=0, then NT = NT-1

T3

T4 If NT >=0, then NT = NT-1

T5 WRITE NT(0)

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Interference problems

– Uncommitted dependency An uncommitted dependency occurs when one transaction

reads data written by another transaction before the other

transaction commits. An uncommitted dependency is also known

as dirty read because it is caused by one transaction reading

dirty (uncommitted) data. Uncommitted dependency cannot cause a problem unless a

rollback occurs

7

Before A

commits,

the

User

cancels

transaction

and A

issues a

ROLLBACK

The value

used by

transaction B

is now a

Phantom

value and B

is denied a

reservation

of

truck

Transaction A Time Transaction BREAD NT(2) T1

If NP >=0, thenNT = NT-2

T2

WRITE NT (0) T3

T4 READ NT(0)ROLLBACK T5

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Interference problems

– Incorrect summary A Incorrect summary problem occurs when a transaction

changes values but reads other values after another transaction

changes the values.

8

Transaction A Time Transaction B

READ X(10) T1

X=X-1 T2

WRITE X(9) T3

T4 READ X(9)

T5 SUM=SUM+X

T6 READ Y(3)

T7 SUM=SUM+Y(3)

READ Y(3) T8

Y=Y+1 T9

WRITE Y(4) T10

Transaction B

reads X after

it is

subtracted by

1 and read Y

before it is

added by 1.

Hence a

wrong

summary

results.

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Interference problems

– Nonrepeatable read A nonrepeatable read problem occurs when a transaction

reads the same value more than one time. In between reading

the data item, another transaction modifies the data item. The

second retrieval contains a different value than the first retrieval

because of the change made by the other transaction.

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User 2: changes data referenced

in the query result of user 1

User 1:

Executes

query with

record

conditions

User 1: re-

executes the

query;

different data

returned

Transaction A Time Transaction B

READ NP(80) T1

T2 READ NP(80)

T3 NP=NP-20

T4 WRITE NP (60)

READ NP(60) T5

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Interference problems

- Phantom read A phantom read problem occurs when a transaction executes a query

with a record conditions. Then another transaction inserts or modifies

data the query would retrieve. Finally, the transaction executes the same

query again. The second query execution retrieves different records than

first execution. The new and changed records are phantom because they

did not exist in the result of the first query execution.

The nonrepeatable read and phantom read problems are slightly

different. A nonrepeatable read problem would occur if another user

changed the value of a column of a query row so that the query returns a

different value in the next execution.

A phantom read problem would occur if a new row is inserted that

matches a condition in a query so that the query retrieves an additional

row in the next execution. Similarly, a row that is deleted would contribute

to similar problem. The key difference is the row condition requirement

for the phantom read problem.

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Design for concurrency

How to design your database application with concurrency in mind:

Minimize transaction size: the smaller a transaction is the less likely it

is to interact with other transactions.

Limit transaction operations: the transaction should accomplish one

task and should include only those statements needed to accomplish

that task.

Access resources in a consistent order: you can minimize the

possibility of two transactions interfering with or mutually blocking each

other if whenever possible you write transactions to access resources in

the same order.

Minimize resource access time: keep the time that you hold a

resource open for access to a minimum by going in, doing what you

need to do, and then getting back out as quickly as possible.

Watch when you run resource-intensive operations: whenever

possible, schedule operations that include long-running transactions to

run after hours or during off-peak times.

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Concurrency Control Tools - Locks

A lock is a fundamental tool of concurrency control.

Locks provide a way to prevent other users from accessing

database item in use. A database item can be a row, block, a

subset of rows or even an entire table.

Before accessing a database item, a lock must be obtained.

Other users must wait if trying to obtain a conflicting lock on the

same item.

A shared(S) lock must be obtained before reading a database

item.

An exclusive(X) lock must be obtained before writing.

Any number of users can hold a shared lock on the same item

but only one user can hold an exclusive lock.

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Concurrency Control Tools

– Locking Conflict Locking conflicts (on the same item):

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User 2 requests

User 1 holds S Lock X Lock

S Lock Lock granted User 2 waits

X Lock User 2 waits User 2 waits

Lock usage:

- Obtain appropriate kind of lock before accessing database item

- Wait if another transaction holds a conflicting lock

Shared lock: conflicts with exclusive locks

Exclusive lock: conflicts with all other kinds of locks

Lock table:

- Details about locks held by transactions

- Concurrency control manager maintains

- Lock: insert a lock record

- Release (unlock): delete a lock record

Concurrency control manager in

the database system maintains

the lock table

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Concurrency Control Tools

– 2 Phase Locking protocol Condition of 2PL:

Before reading or writing to a data item, the transaction must acquire

the applicable lock to the data item

Wait if a conflicting lock is held on the data item

After releasing a lock, the transaction does not acquire any new

locks

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Time

Growing phase

BOT EOT

Shrinking

phase

Lo

cks h

eld

At the beginning of transaction (BOT),

a transaction has no locks.

Two phases:

Growing phase: acquire locks

without releasing any locks; not

necessarily linear

Shrinking phase: release locks

without acquiring new locks

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2PL illustration – Truck booking

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Reserve

truck A

Lock A Lock B Return

truck B

Unlock ACommit

Growing

Phase

Shrinking

Phase

Unlock B

Reserve truck A and Return truck B

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Deadlock – Problem of Mutual

waiting Deadlocks is a problem of mutual waiting for some item that is locked.

If a deadlock is not resolved, the involved transaction would wait

forever.

How deadlocks can be controlled by a DBMS:

1. Deadlock detection: The system checks if a state of deadlock

actually exists. If so, the most recent transaction is forced to restart.

2. Timeout Policy: abort transactions that wait more than the timeout

period. (Note: Not easy to determine timeout interval)

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Transaction A Time Transaction B

XLock TR1 T1

T2 XLock TR2

XLock TR2 (wait) T3

T4 XLockTR1 (wait)

- Transaction involving multiple

database items

- Transaction A: lock on TR1, waiting

on TR2

- Transaction B: lock on TR2, waiting

on TR1

Can involve more than two users but the

pattern is more complex

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Deadlock illustration – Truck booking

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Lock A Waiting to

Lock B

Lock B Waiting to

Lock A

There is a deadlock for both transactions TA and TB because

both are waiting for each other to release the lock!

Transaction TA: Reserve truck A and Return truck B

Transaction TB: Reserve truck B and Return truck A

Reserve

truck A

Reserve

truck B

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Problem Statement

The properties of transactions are essential for maintaining the

reliability of database transactions. This is especially so when

multiple users update the database concurrently. ACID

properties of database transaction ensures that the reliability of

database transaction is maintained.

Interference problems such as lost update, uncommitted

dependency (dirty read), Incorrect summary, non repeatable read

and phantom read occurs if concurrency control was not

implemented.

A two-phase locking protocol can be used as a concurrency

control tool.

However, do take note that problems of mutual waiting may

occurs due to locking. Deadlock detection and timeout policy

may be introduced to prevent the problem.

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Learning Outcomes

Explain the ACID transaction properties

Explain interference problems and problem of mutual waiting in

database transaction

Explain the importance of concurrency control and the role of

locking to prevent interference problem among multiple users

SCHOOL OF ENGINEERING

P08 – The network is down again!

E223 : IT FOR SUPPLY CHAIN MANAGEMENT

Copyright © 2009 School of Engineering, Republic Polytechnic, Singapore

All rights reserved. No part of this document may be reproduced, stored in a retrieval

system, or transmitted, in any form or by any means, electronic, mechanical,

photocopying, recording or otherwise, without the prior permission of the School of

Engineering, Republic Polytechnic, Singapore.

The network is down again! Wyprol Logistics is a logistics company that provides transportation services to freight forwarding companies. With extensive use of IT for its logistical operations, it demands very little disruption for system failure. However, a heavy thunderstorm in the afternoon triggered serious hardware failure in some important network equipment in the data centre. As a result, no computers can access the internet or the company’s shared folder. No data exchange and email could take place and no transportation route can be planned for deliveries and collection activities. Currently, the network engineers are reconfiguring the servers and testing out the network. It may take a least half a day to restore the internet connectivity fully. Douglas, the logistics analyst suggested that you may use of LAN cables or USB to USB network cable to share information between your laptop and other laptops. Jenny, the operations staff suggested that you may also make use of built-in Bluetooth in your laptop. Weiming, the supply chain engineer further suggested that you may also use your laptop to share your folders as long as all the laptops have wireless cards and you can do without cable. Some information to be shared may be up to 2GB or more. Explore the various alternatives and make use of the best approach to share your information with them. You should illustrate your approach to your manager.

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P08

The Network is down again!

E223 – IT for Supply Chain Management

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Network and connectivity A network is defined as a series of devices interconnected over a

connection path. Devices usually means computers and connection

path can be wired or wireless.

2

Laptop Ethernet port Network/Ethernet cable

Plugs in

USB port USB cable

Plugs in

Wired

connection

path

Wireless Access Point

Wireless

connection

path

Laptop wireless

Network Access Card

Wireless

connection

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Network Media Type:

Cable – Straight-through Cable

3

When a PC is connected directly to a network hub or switch (or

something similar), a straight-through cable can be used.

Network Interface Card (NIC)Hub or switch Laptop Ethernet port

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Network Media Type:

Cable – Crossover Cable

4

When a PC is directly connected by a cable to another PC, a crossover

cable must be used. Because of the data transmit and receiving

methods, the wires used for transmitting and receiving data signals

must be crossed for some devices.

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USB Networking Cable/USB-USB

bridged cable The one used to connect two PCs is called “bridged” (or “USB

networking cable”), because it has a small electronic circuit in the

middle allowing the two PCs to talk to each other.

As for speed, the bridge chip can be USB 1.1 (12 Mbps) or USB 2.0

(480 Mbps).

Note: the standard Ethernet network works at 100 Mps, so the USB 2.0

cable will provide you a transfer rate almost five times higher than a

standard network connection.

5

Bridge chip

used in cable

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Wireless technology for very short

range Bluetooth and Ultra Wide Band (UWB) are wireless standards

designed for very short range. The purpose is to eliminate

cables between devices such as PDAs and computers, allowing

for synchronization between printers, mobile telephone headsets

and other devices.

6

Bluetooth device

Class

Maximum Permitted

Power

mW (dBm)

Range

(approximate)

Class 1 100 mW (20 dBm) ~100 metres

Class 2 2.5 mW (4 dBm) ~22 metres

Class 3 1 mW (0 dBm) ~6 metres

Version Data Rate

Version 1.2 1 Mbit/s

Version 2.0 + EDR 3 Mbit/s

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Wireless Technologies Wireless Networks - Wireless communications use radio frequencies

(RF) or infrared (IR) waves to transmit data. Wireless networks (the

RF kind, which are by far the most common) are based on the same

technology as your FM radio in a car, but with very sophisticated

technologies to transmit data at very high speeds.

If your PC does not come with a pre-installed wireless NIC, you will

have to install one before your computer can communicate with a

wireless network. Wireless allows many new options for network

designers because no cable is required to connect end stations (which

is great for installation in houses or offices where cabling would be

difficult or expensive).

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WLAN Standard

8

A WLAN’s Signal Decreases

as Distance Increases

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Wireless Network at home and office

using WLAN(IEEE802.11g)

9

Wireless

access point

Wireless at home Wireless at office

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Wireless Network at a warehouse

using WLAN (IEEE802.11g)

10

The transmission of data

from the van’s terminal,

which includes all of the

important information

regarding each pick-up, is

completed before the first

package is unloaded from

the van.

Wireless

network

Wireless at a warehouse

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Wireless Network Topologies:

Ad Hoc Mode Ad-hoc Mode

In ad hoc mode (also referred to as peer-to-peer mode), wireless

network devices communicate directly with each other. There is no

central access point device involved. There are no physical placement

requirements, as long as the devices are in range of each other.

Devices can relay messages between each other, extending the range

of the network.

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Wireless Network Topologies:

Infrastructure Mode Infrastructure Mode

Infrastructure mode lets you combine wired and wireless networks

through the use of a wireless access point (WAP). The WAP

provides a central access point for the wireless computers, and it also

passes data to and from the wired network. However, this isn’t the only

possible configuration. An infrastructure mode network can be

completely wireless, consisting of just a WAP and the wireless clients

mode.

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Wireless Network Topologies:

Wireless Mesh A wireless mesh, which is a set of WAPs or other transmission towers

with overlapping ranges, can take various forms. The computer as

shown in the figure below is in the range of 2 different WAPs can could

potentially connect with either of them.

13

E.g.

The network of cell phone towers is

configured as a wireless mesh. This

is done so that you do not lose

your call as you move out of the

range of one cell tower to another.

Wi-Fi hotspots are often set up as

wireless meshes (e.g. hotel), so that

you can move around the location

without losing your connectivity.

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Cellular Network (3G)

14

The data from the PDA is transmitted

to a cellular tower, which then

retransmits the data back to the van.

This technology is based on a

standard known as 3G (third

generation) technology, which uses

100% digital transmission for both

voice and data.

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Wireless Metropolitan Network

(WMAN)

15

A single WMAN link covers a distance of up

to 35 miles and can be used to carry data,

digitized voice, and video signals. WMANs

are based on the IEEE 802.16 Fixed

Broadband Wireless standard and use

wireless transmissions for data

communications. These networks use small

custom antennas on the roof of each

building in the WMAN. The signal is

transmitted to the antenna of the receiving

building, which can be as far as 35 miles (56

kilometers) away. The transmission speed

can be as high as 75 Mbps at distances of

up to 4 miles (6.4 km), and 17 to 50 Mbps

(depending on link quality) at distances

over 6 miles (10 km).

The use of the antennas substantially

reduces the cost over traditional wired

connections, which require installation of

the infrastructure under city roads, are

more prone to damage, and are more

expensive to maintain.

is based on 802.16 standards

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Satellite Network

16

In satellite communications, a device

called a repeater is located in the

satellite itself A repeater simply

repeats the same signal to another

location. An earth station transmits

to the satellite at one frequency

band, and the satellite regenerates

and transmits (repeats) the signal

back to Earth on another frequency.

The transmission time needed to

repeat a signal from one Earth

station to another is approximately

250 milliseconds.

The satellite can send time sensitive

data such as route alerts to warn of

traffic delays or changes in pick-up

schedules. The van’s own onboard

computer, which monitors engine

performance and other vehicle

systems, can perform diagnostic

checks and transmit the results back

to the call centre over the satellite

connection.

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Comparison – Wireless technologies

Wireless

Technology

Range (Transmission

distance)

Speed

RFID 1 inch (2.5 cm) to 300 feet

(100m) depending on

frequency and tag

Usually a few thousand bits

per second (kbps)

Bluetooth Version 1.x : 33 feet (10 m)

Version 2.0 : 30 m

Version 1.x: 1 Mbps

Version 2.0: 2.1 Mbps

UWB 150 feet (50 m) 100 Mbps

WLAN 802.11b 375 feet (112 m) 11 Mbps

WLAN 802.11g 300 feet (90 m) 54 Mbps

WMAN 802.16

Wi-Max

35 miles (56 km) 75 Mbps

2.5G digital cellular Nationwide 384 Kbps

3G digital cellular Nationwide 2 Mbps

Satellite Worldwide 250 millisecond delay

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WLAN Attack

Attack against WLANs:

Hardware theft. A wireless device may contain information that can

assist someone into breaking into the network.

Access Point (AP) Impersonation. A client machine may

authenticate itself to an access point but not the other way round.

Hence a rogue AP can impersonate a valid device, tricking a client to

associate with it. Information from the clients can then be obtained.

This is called man-in-the-middle attack.

Passive monitoring. Data transmission can be monitored to acquire

information such as address of AP and the hacker can build a profile

of a network, based on statistical analysis to break into a network.

Denial of Service (DoS) attacks. An unauthorized user can use this

information to flood the network with transmissions and deny others

access to the AP using this attack.

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WLAN Security

Network security is concerned mainly with the following two elements:

1.Confidentiality. Information should be available only to those who

have rightful access to it.

2.Authenticity and integrity. The sender of a message and the

message itself should be verified at the receiving point.

Security measures:

Authentication. This is a process that verifies that the client device has

permission to access the network. Only those Clients that know the SSID

are authenticated as valid users and allow to connect to the network.

Privacy. This ensures that transmissions are not read by unauthorized

users. It can done through data encryption that scrambles the data in a way

that it cannot be read and can only be decoded by the intended recipients.

There are several privacy standards such as WEP, WPA, TKIP, WPA2, EAP.

Reduce WLAN transmission power.

Use Antivirus and antispyware software

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Wireless settings and security issues

(Illustrations)Situation 1 Situation 2 Situation 3 Situation 4

Wireless Setting:

-Enable SSID broadcast

-Default SSID (e.g.

LINKSYS)

-Encryption: None

-MAC Filtering: None

Wireless Setting:

-Disable SSID

broadcast

-Default SSID (e.g.

ABC Home)

-Encryption: None

-MAC Filtering: None

Wireless Setting:

-Disable SSID broadcast

-Random SSID (e.g.

AxzRS)

-Encryption: 128 WEP

Encryption

-MAC Filtering: None

Wireless Setting:

-Disable SSID broadcast

-Random SSID (e.g.

zxzRS)

-Encryption: WP2

Encryption

-MAC Filtering: Yes

Security Issue:

-Anyone with a

laptop/desk top can

connect to the network

Security Issue:

-Would be able to

keep most non-

hackers out of the

network

- All information

would be sent in

clear text

Security Issue:

-Network is secure enough

for most people

-Data is encrypted

Security Issue:

-Highest security among

all.

-More complex to

implement.

Comment:

Not secure

Comment:

Still Vulnerable

Comment:

Secure enough for most

people but a good hacker

may still be able to attack.

Minimum security settings.

Comment:

Quite secure

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WiMAX Attack

Attack on WiMAX:

A fundamental flaw in the authentication mechanism used by

WiMAX's privacy and key management (PKM) protocol is the lack of

base station (BS) or service provider authentication. This makes

WiMAX networks susceptible to man-in-the-middle attacks, exposing

subscribers to various confidentiality and availability attacks.

An attacker can use methods to forcibly disconnect legitimate

stations. This is similar to the de-authenticate flood attacks used

against WLAN.

Rogue Base Stations

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WiMAX Security

Security measures:

WiMAX deployments will use licensed RF spectrum, giving them

some measure of protection from unintentional interference.

Each subscriber station (SS) must have a X.509 certificate that will

uniquely identify the subscriber. The use of X.509 certificates

makes it difficult for an attacker to spoof the identity of legitimate

subscribers, providing ample protection against theft of service.

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Problem Statement

In view of the urgency of the matter, configuring the laptop in ad hoc mode

would be the best choice as:

It does not require any network cable

You do not need to obtain a wireless access point or any other network

devices (such as a switch or router) to set up the network

Yet, you can share the ad hoc network instantly with more than 1 client

computer

USB networking cable is a good choice if the data is shared among very few

client computers. The transfer rate is faster and can be up to 480MBps.

BlueTooth is not suitable because the transfer rate is slow (around 3Mbits

per second).

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Learning Outcomes

Compare different network physical media and different kind of

wireless network topologies and technologies used today

Explain different context in which wireless technology is applied

Explain WLAN and WiMAX attack and security

SCHOOL OF ENGINEERING

P09 – Pivot your way!

E223 : IT FOR SUPPLY CHAIN MANAGEMENT

Copyright © 2009 School of Engineering, Republic Polytechnic, Singapore

All rights reserved. No part of this document may be reproduced, stored in a retrieval

system, or transmitted, in any form or by any means, electronic, mechanical,

photocopying, recording or otherwise, without the prior permission of the School of

Engineering, Republic Polytechnic, Singapore.

Pivot your way! Wealth365º is a fresh flower packaging company that packs and supplies flowers to retail stores and supermarkets locally. All the orders for flowers must be made online through internet sales. It has a central pack and distribute centre which stores the fresh flowers on a short-term basis before distributing to respective customers. Major customers include Sunrise Flora, Exquisite Flora, Qual Flora and Fresh Flora. Currently, the company uses an operations database to capture the information for its daily distribution operations. However, there were certain occasions in which the end users experience slowness while generating monthly sales reports from the database. This is quite predominantly during festive period. In some situations, both the report generation and daily operations completely stalled. The management has decided to look at the problem closely because they require the operations database to be operational and up-to-date while data retrieval for decision-making should be available whenever they need it. The sales data for data analysis should also be viewable in different formats. It should be able to support summary calculations and show data in running totals, etc. As a senior project analyst, you are tasked to examine the current situation using the operations data base and also provide the solution for data analysis to your manager.

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P09

Pivot your way!

E223 – IT for Supply Chain Management

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Transaction Processing Versus

Decision Support Transaction processing allows organizations to conduct daily

business in an efficient manner.

Operational or production database are used in transaction to assist

with decisions such as tracking orders, resolving customer

complaints and staffing requirements

It involves detailed data about business processes

Decision supporting processing helps management provide

medium-term and long-term direction for an organization.

Management needs support for decisions about capacity planning,

product development, store location, product promotion.

Decision support needs a broad view that integrates business

processes.

Because of different requirements, operational database and

decision support database are separated.

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Operational database versus Data

warehouse Data warehouse refers to a central data repository where data

from operational databases and other sources are integrated,

cleaned and standardized to support decision-making. These

transformational activities are essential for achieving benefits.

3

Characteristics Operational Data Warehouse

Currency/Recency Current Historical

Detail Level Individual Individual and Summary

Orientation Process Orientation Subject Orientation

No. of records processed Few Thousands

Normalization Level Mostly Normalized Frequent Violation of

BCNF - DB Normalization

Update Level Volatile Nonvolatile (refreshed)

Data Model Relational Multi-dimensional

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Data warehouse versus Data Mart

4

A data mart is a data warehouse that is limited in scope.Characteristics Data Warehouse Data Mart

Scope Application independent Specific DSS application

Centralized Decentralized

Planned Not Planned

Data Historical, detailed,

summarized

Some history, detailed, summarized

Lightly de-normalized Highly de-normalized

Subjects Multiple subjects 1 central subject of concern to user

Sources Many internal and external

sources

Few internal and external sources

Other Flexible Restrictive

Data-oriented Project-oriented

Large Start small, becomes large

Long life Short life

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Architecture of Data warehouse

- 2-tier architecture In a two-tier data warehouse architecture, operational data are transformed

and then transferred to a data warehouse. The two-tier architecture can

have performance problems for large data warehouses with data-intensive

applications for decision support.

5

Tier 1Tier 2

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Architecture of Data warehouse

- 3-tier architecture

6

Many large organizations use a three-tier data warehouse architecture.

Departmental users generally need access to small portions of data

warehouse, instead of the entire warehouse.

Tier 1Tier 2Tier 3

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Data Characteristics – Status versus

Event data

Shipment Ref No Shipment info Shipment Status

7

Consider a database with the following Shipment table:

Current status:

AXDF1298740 10 cartons of Gerbera Daisy In-Transit

Note:

Database Action can be: insert, update or delete

Database Action: Update

Update Shipment set Shipment Status = “POD”

Where Shipment Ref No = “AXDF1298740”

Description of event : Shipment delivered

AXDF1298740 10 cartons of Gerbera Daisy POD

New Status:

Status data

Event data

School of Engineering

Data Characteristics – Transient

versus Periodic data With transient data, changes to existing records are written over previous

records, thus destroying the previous data content.

Periodic data are never physically altered or deleted once they have been

added to the store. E.g. once the shipment is delivered, the status is not

updated anymore.

8

AXDF1298740 10 cartons of Gerbera Daisy In-Transit

AXDF1298740 10 cartons of Gerbera Daisy Reach Warehouse

AXDF1298740 10 cartons of Gerbera Daisy POD

AXDF1298740 10 cartons of Gerbera Daisy POD

Transient data

Transient data

Periodic data

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Relational versus Multidimensional

Representation of dataRelational Representation of data

(2-Dimensional)

Multi-dimensional Representation

of data

9

(3 –Dimensional) Data Cube

Multidimensional Representation

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Multidimensional Terminology

A data cube consists of cells containing measures (numeric

values such as unit sales amounts) organized by subjects called

dimensions (e.g. Product, Location, Time).

Measures support numeric operations such as arithmetic,

statistical calculations, simultaneous equations.

Dimensions can have hierarchies composed of levels. E.g.

Location dimension may have hierarchy composed of levels - country,

state, city.

Time dimension may have hierarchy composed of year, quarter, month,

date.

10

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Data Cube Operations

– Slice and Dice Slice – In slice operation, one or more dimensions are set to specific

values and the remaining data cube is displayed. E.g. Time

dimension is set to Jan-2008 and the other two dimensions (Product

and Customer) are shown.

Dice - The dice operator replaces a dimension with a subset of

values of the dimension. E.g. Sales of Gerbera

11

Product

Dimension

Customer Dimension

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Data Cube Operations

– Drill down Drill-down – The drill down operator allows users to navigate

from more general view to more specific level. E.g. Drill down

view of Customer dimension. In this case – Exquisite Flora.

12

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Data Cube Operations

– Roll-up Roll-up - The roll-up move from more specific to more general

view of a hierarchical dimension. E.g. roll-up view of Customer

Sales

13

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Data Cube Operations - Pivot

Row label :

Month, Product Name

Column Label:

Customer Name

Values:

Sum of Sales

14

Pivot supports rearrangement of

the dimensions in a data cube.

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Data Cube Operations

- Pivot (Alternative view #1) Row Label:

Customer Name, Month

Column Label:

Product Name

Values:

Sum of Sales

15

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Data Cube Operations

- Pivot (Alternative view #2)

16

Row Label:

Customer Name,

Product Name

Column Label:

Month

Values:

Sum of Sales

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Advanced Calculation in Pivot Table

- Show values as % of total

17

Row Label:

Product Name, Month

Column Label:

Customer Name

Values:

Sum of Sales

Value field settings:

Show values as %of

total

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Advanced Calculation in Pivot Table

- Show values as Running Total In

18

Row Label:

Product Name, Month

Column Label:

Customer

Values:

Sum of Sales

Value field settings:

Show values as Running

Total in Month

Sunflower Sales for Exquisite Flora :

Dec-08 Sales = 130

Jan-09 Sales= 135

Feb-09 Sales= 140

Mar-09 Sales= 130

Apr-09 Sales= 140

The running total shows the cumulative

sum in each month with the base

month as Dec-08

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Advanced Calculation in Pivot Table

- Difference From a base dateRow Label:

Customer, Product Name

Column Label:

Month

Values:

Sum of Sales

Value field settings:

Difference from a base

date – Dec-08

19

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Advanced Calculation in Pivot Table

-Difference From previous month

20

Row Label:

Customer, Product Name

Column Label:

Month

Values:

Sum of Sales

Value field settings:

Difference from Previous

(i.e. Feb from Jan, Mar from

Feb)

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Advanced Calculation in Pivot Table- Using Index to show relative Importance

21

Index of sales:

Sunflower is more

importance to

Qual Flora than Exquisite

Flora. Qual Flora (Index =

1.243) compare to

Exquisite Flora (Index =

1.17)

Row Label:

Product Name, Month

Column Label:

Customer

Values:

Sum of Sales

Value field settings: Index

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Visualize data in a Pivot Table using

Pivot Chart A pictorial distribution associated

with the customer that has

products which contribute to the

highest sales for the company

(1st quarter of 2009)

22

A pictorial distribution of

comparison between two products

which has the highest sales (Sun

flower) and lowest sales (Gebera).

(1st quarter of 2009)

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Problem Statement

Operations and decision-making application should use different

databases because the requirement is different. A transactional

database supports real-time operations while a data warehouse

provide functionalities for decision-making based on historical data.

A 3-tier architecture is better because it is more robust and

departmental users only need to access a small portion of data

warehouse call data mart.

Pivot Table in Excel is a useful tool that support data analysis. It

support various data cube operations such as Slice, Dice, Roll-up,

Drill-down. It also provide alternative views – pivot view and

summary calculations. For advanced calculations, it also supports

running totals, %, difference and using index to show relative

importance.

Pivot chart can also be used to visualize the data found in pivot

table.

23

School of Engineering 24

Learning Outcomes

Explain the conceptual difference between operational database

and data warehouse

Explain architectures to apply data warehouse technology in

organization

Discuss data characteristics and the representation and

operations of data cubes

Describe pivot table data analysis and calculation

SCHOOL OF ENGINEERING

P10 – Bundle for speed!

E223 : IT FOR SUPPLY CHAIN MANAGEMENT

Copyright © 2009 School of Engineering, Republic Polytechnic, Singapore

All rights reserved. No part of this document may be reproduced, stored in a retrieval

system, or transmitted, in any form or by any means, electronic, mechanical,

photocopying, recording or otherwise, without the prior permission of the School of

Engineering, Republic Polytechnic, Singapore.

Bundle for speed! Aeksia Logistics is a well known 3PL in the Asia region. It owns several warehouses and provides different types of warehousing services. Currently the management is puzzled by the fact that although the warehousing facilities is good and the technology used is quite advanced, the order picking process for outbound shipment is not fast enough. As such, it is not able to meet certain delivery targets set by the customer, YZH Corp. In order to improve on the order picking speed and meet the customer’s delivery target by the next meeting, the management of Aeksia Logistics has decided to examine the current items in the warehouse to see if there is any similarity in the demand. This would result in better zoning and hence increase the speed of order picking. As part of the new initiatives, the item AZ-111 is identified. The company has identified five items: ZP-120, ZA-850, ZQ-108, ZC-339 and ZH-096. 13 Order transactions for the past 1 month were obtained. Which item should the company consider to put in the same zone with AZ-111? In the meanwhile, Aeksia Logistics has also acquired a new piece of software to be used for the same analysis. Describe the steps taken to accomplish the same task.

Transactions showing items for order picking:

Order Transactions

Items

ZP-120 ZA-850 ZQ-108 ZC-339 ZH-096 AZ-111

1 ZP ZA ZC ZH

2 ZQ ZH AZ

3 ZP ZA ZQ ZC

4 ZP ZA ZQ AZ

5 ZP ZA ZQ ZC ZH AZ

6 ZA ZC ZH AZ

7 ZP ZA ZQ ZH

8 ZP ZQ ZC AZ

9 ZQ ZH AZ

10 ZP ZA ZQ ZC ZH

11 ZP ZA ZQ ZC

12 ZP ZH AZ

13 ZP ZA ZQ ZC AZ

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P10

Bundle for speed!

E223 – IT for Supply Chain Management

School of Engineering

Data Mining and Techniques

Data mining is essentially the analysis of statistical data, usually

using enormous data set

2

Data mining

Techniques

Association

Classification

Clustering

AnalysisPrediction

Analysis

Sequential

pattern

analysis

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Market Basket Analysis – What is it?

Market Basket Analysis is a data mining technique call association.

In Association, the relationship of a particular item in a data transaction

on other items in the same transaction is used to predict patterns. For

example, if a customer purchases a laptop PC (X), then he or she

also buys a mouse (Y) in 60 percent of the cases.

This technique has been widely applied to grocery store operations (as

well as other retailing operations, including restaurants).

Two kind of patterns can be predicted:

Tendencies of customers to purchase items together

Sequential relationships: such as purchasing a house followed by

purchases of furniture

3

Results in a form of

knowledge discovery

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Application of Market Basket Analysis

By knowing the patterns such as what products tends to

purchase together, it can help the supermarket manager to

predict the kind of items being purchase. This has several

benefits

Cross selling of product (knowing which product tends to

purchased together)

Help in the layout of the product in the store (e.g. put the most

saleable items near to the store entrance so that it is more

visible) – Affinity Positioning

Stocking the right items to increase sales

Reduce excess inventories

Applications in warehouse: Decision to place similar items near

to one another for efficient order picking

4

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Market Basket Analysis - Process

5

More detailed

More general

Same Level: Kiwi, Dragon Fruit, Strawberry

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Current Sales transactions

Transactions showing items for order picking:

6

Number

of transactions =13

Order

Transactions

Items

ZP-120 ZA-850 ZQ-108 ZC-339 ZH-096 AZ-111

1 ZP ZA ZC ZH

2 ZQ ZH AZ

3 ZP ZA ZQ ZC

4 ZP ZA ZQ AZ

5 ZP ZA ZQ ZC ZH AZ

6 ZA ZC ZH AZ

7 ZP ZA ZQ ZH

8 ZP ZQ ZC AZ

9 ZQ ZH AZ

10 ZP ZA ZQ ZC ZH

11 ZP ZA ZQ ZC

12 ZP ZH AZ

13 ZP ZA ZQ ZC AZ

Number

of items =6

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Can we simply choose the items with

the highest transactions? Can we simply choose the product with the highest occurrence

with AZ-111 in the pick list?

7

Product Number of occurrences with

AZ-111 in the pick list

ZP-120 5

ZA-850 4

ZQ-108 6

ZC-339 4

ZH-096 5

Can we simply

choose this?

-Popularity

-Similar items

And satisfy the

criteria set by

the company?

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Combination

Combination – How many ways a few items can be formed from a

group of items

It is represented by nCr =

meaning number of n objects taken r at a time

In this case, we have a group of 6 items (ZP-120, ZA-850, ZQ-108,

ZC-339, ZH-096, AZ-111). Hence, number of ways to choose 2

different items out of 6 items:6C2 = =

= 15

Using Excel:

= Combin(6,2) = 15

8

)!26(!2

!6

)!(!

!

rnr

n

24*2

720

Or Excel function:

=Combin(n,r)

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Concurrence Table of items -

From current sales transaction Co-occurrence table – shows number of times any pair of items

were purchased together

9

Items ZP-120 ZA-850 ZQ-108 ZC-339 ZH-096 AZ-111

ZP-120 10 8 8 7 5 5

ZA-850 8 9 7 7 5 4

ZQ-108 8 7 10 6 5 6

ZC-339 7 7 6 8 4 4

ZH-096 5 5 5 4 8 5

AZ-111 5 4 6 4 5 8

Steps:

1. Compute the diagonal values first (E.g. ZQ appears 10 times, ZH appears 8 times in the

transactions)

2. Computer either the upper half or lower half with respect to the diagonal values. The

other half of the values would be the same.

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Support (Calculations) Support is a measure of how often the collection of items in an

association occurs together as a percentage of all the transactions

Support = Number of transactions with all the items in the rule

Total number of transactions

Since we want to find out the which product should be bundled and place in

close proximity for order picking, we need to consider the transactions with

AZ.

List down all the transactions with AZ (meaning bundle with AZ):

ZP and AZ (Note: Written as ZP=>AZ for simplicity)

ZA and AZ

ZQ and AZ

ZC and AZ

ZH and AZ

Note: ZP=>AZ is also known

as rule. ZP is known as the condition; AZ is known as the result

ZP=>AZ It means if ZP is picked, AZ would also be picked.

10

Number of

transactions

For each of the

rule listed

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Support Tabulation From the co-occurrence table, ZP=>AZ = 5.

Hence

Probability of Support value = 5/13 = 0.385

Percentage of Support value = 38.5%

Tabulate the list and support values into a table:

11

Combination of

values

Probability of

support

% of support

ZP=>AZ 5/13=0.385 38.5%

ZA=>AZ 4/13=0.308 30.8%

ZQ=>AZ 6/13=0.462 46.2%

ZC=>AZ 4/13=0.308 30.8%

ZH=>AZ 5/13=0.385 38.5%

ZP=>AZ has a support of 38.5%

It means that ZP and AZ occurs together in 38.5% of the total

transaction

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Confidence

Confidence is defined as

Number of transaction with all the items in the rule (condition & result)

Number of transaction with just the items in the condition

It is a measure of how often the relationship holds true.

For ZP=>AZ,

No of transactions containing ZP and AZ = 5

No of transactions containing ZP only = 10

Hence, confidence = 5/10 = 0.500

- Written as P(AZ|ZP)

ZP=>AZ has a confidence of 50%

It means that when ZP is

picked, there is a 50.0%

chance that AZ will be picked.

12

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Confidence Tabulation

Tabulate all the confidence values into a table

13

Combination of

values

Confidence % Confidence

ZP=>AZ 5/10 = 0.500 50.0%

ZA=>AZ 4/9 = 0.444 44.4%

ZQ=>AZ 6/10 = 0.600 60.0%

ZC=>AZ 4/8 = 0.500 50.0%

ZH=>AZ 5/8 = 0.625 62.5%

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Lift

Lift tells how much better a rule is at predicting the result than

just assuming from the result. If Lift is >1 it is better at predicting

the result than random chance. If Lift is < 1, it is worse.

Lift =

P(Condition and Result)

P(Condition) x P(Result)

For ZP=>AZ,

Support = P(ZP=>AZ) = 5/13

= 0.385

P(ZP) = 10/13 = 0.769

P(AZ) = 8/13 = 0.615

Hence, Lift = 0.385/(0.769x0.615)

= 0.814

14

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Lift Tabulation and Calculation Tabulate lift values into a table

15

Combination of values Lift

ZP=>AZ 0.385/(0.769x0.615) = 0.814

ZA=>AZ 0.308/(0.692x0.615) = 0.724

ZQ=>AZ 0.462/(0.769x0.615) = 0.977

ZC=>AZ 0.308/(0.615x0.615) = 0.814

ZH=>AZ 0.385/(0.615x0.615) = 1.018

Lift can also be viewed as

Lift =

Support

[P(Condition) x P(Result)]

E.g.

For ZP=>AZ

Lift =

P (ZP=>AZ) = 0.385

[P(ZP) x P(AZ)] 0.769x0.615

=0.81Or

Lift =

P (Condition and Result)

[P(Condition) x P(Result)]= Confidence

P(Result)

E.g.

For ZP=>AZ

Lift =

P (AZ|ZP) = 0.50 =0.81

P(AZ) 0.615

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Problem Statement

Tabulate the measurements for support, confidence and lift

Although ZQ=>AZ shows a highest support (46.2%) and the confidence

satisfy the requirement but the lift is less than 1. For ZH=>AZ, support

=38.5% and confidence = 62.5% satisfy the condition and the lift is >1

(Important).

Hence item (ZH-096) should be bundled with item (AZ-111) to satisfy

at least 35% of support and 60% of confidence.

16

Combination

of values

% of support % Confidence Lift

ZP=>AZ 38.5% 50.0% 0.814

ZA=>AZ 30.8% 44.4% 0.724

ZQ=>AZ 46.2% 60.0% 0.977

ZC=>AZ 30.8% 50.0% 0.814

ZH=>AZ 38.5% 62.5% 1.018

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Problem Statement - Using a data

mining software to obtain the result

17

Step 1: Copy the data to Excel and

save as a .csv file.

Step 2:

Load the data and click import now

School of Engineering

Problem Statement - Using a data

mining software to obtain the result

18

Step 3: Configure the followings:

Search for: RULES

Search by: LIFT

Filter out: NONE

Maximum size: 1

LHS: Select all allowed values

RHS: Select X only

Click on GO button

Step 4: A text file with extension

.out is generated. Choice rank in

order of lift (as specified)

Compare the values

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Problem statement – If any 3 items were

to be picked together (AZ not included)

19

Satisfy the minimum

support of 30%,

minimum confidence of

60% and lift must be >1

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Problem statement – If 3 items were to

be picked together (with AZ included)

20

Satisfy the minimum

support of 30%,

minimum confidence of

60% and lift must be >1

School of Engineering 21

Learning Outcomes

Define data mining and applications of Market Basket Analysis

Utilize Co-occurrence table and combination in Market Basket

Analysis

Calculate Combination, Support, Confidence and Lift in Market

Basket Analysis

SCHOOL OF ENGINEERING

P11 – Faster with Fewer Errors

E223 : IT FOR SUPPLY CHAIN MANAGEMENT

Copyright © 2009 School of Engineering, Republic Polytechnic, Singapore

All rights reserved. No part of this document may be reproduced, stored in a retrieval

system, or transmitted, in any form or by any means, electronic, mechanical,

photocopying, recording or otherwise, without the prior permission of the School of

Engineering, Republic Polytechnic, Singapore.

Faster with Fewer Errors Best Distributor holds the distribution rights for some of the major snack brands in Singapore. These snacks are popular and Best Distributor has been selling it through retailers throughout Singapore for the past 3 years

As the variety of snacks and customers grew with time, Best Distributor’s salesmen begin to find it difficult to keep track of the different snack variety, price, and bulk discounts that can be offered to different retailers. The salesman takes orders on a form, and brings the form back to office where the order is keyed into a financial system for invoice generation. These takes time, and mistakes in the keying of data are made. The invoice generated is used for picking the right products in the warehouse. After the cartons are picked according to orders, the cartons are manually counted and match against what they are supposed to send. These takes time as there are many cartons to be counted and delivery orders to be tallied.

Can both the challenges associated order taking and outgoing process be eased with cost effective technology solutions?

Order Form Shipped To: Shipped From: Store 396-00 AAA Demo Company Pte Ltd (Pasir Ris Central, Pasir Ris MRT Station) Singapore Singapore

Item Material Description UOM Quantity

1040091 Orange Juice Drink 1.3L

BT 20

1040026 Carrot Juice Drink 1.3L

BT 20

1040074 Pomergranate Juice Drink

1.3L BT 13

1240054 Yoghurt Strawberry PK 11

1240054 Yoghurt Mango PK 18

6710037 Beer 8.4% CAN CN 5

670099 Beer 11.6% CAN CN 3

Customer Signature Date/Time Received

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P11

Faster with Fewer Errors

E223 – IT for Supply Chain Management

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Handheld application - Van Sales & Logistics

Applicable for perishable products and/or when the vans

need to travel long distances

Inventory, stock and cash is tallied when van returns back

to office

2

Stock is loaded

on van and

inventory

updated in

PDA/Handheld

Stock is sold to supermarkets and

retailers directly. Inventory is updated

and invoice generated on the spot

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Handheld application – Retail Sales & Logistics

For products with longer shelf life and shorter travel

distances

Opportunity for tracking salesman and for orders to

send back directly to office for product picking

3

Salesman

takes order

from retailer

Salesman returns back to office

to generate invoice/deliver

order for picking

Goods delivered to

retailer

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Handheld/PDA vs Paper Form Orders

Advantages

More accurate product order taking as product identity and description

may be wrongly written

More accurate pricing compared to relying on memory of salesman

Faster transfer of sales data into invoice compared to manual typing,

that causes errors

Can use the data to analyse sales trends and bundling statistics

Less reliance on salesman experience and memory

Disadvantages

Cost involved in implementing PDA/Handheld systems

Training required to use PDA/Handheld systems

Need to update product information and discount information in

database

Salesman has to sync data to generate invoice/picklist

4

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Automated Identification TechnologiesTechnology Example

Optical character recognition (OCR) E.g. Google search engine, Google Book,

Microsoft Office Document Imaging

Barcode Type: EAN13, EAN8, UPCa, UPCe,

Code-39, Code-128

Magnetic Stripe coding E.g. Financial card, Driving Licence

Smart Card Type: Contact, Contactless

E.g. Credit card, Mobile phone SIM card

Biometric Relies on unique personal characteristics

to identify individuals. Popular in security

applications.

RFID Frequency: LF, HF, UHF, Microwave

Protocol: EPC Class 1, ISO 18000-6

5

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Comparison between RFID and

Barcode Technologies

6

RFID Barcode

Line of Sight Not required Required

Dynamic Data Can be changed Cannot be changed

Read Range Longer distance Shorter distance

Read multiple tags at once Yes No

Storage capacity High Low

Multiple reads Yes No

Survivability in hostile environment High Low

Programmability Yes No

Accuracy High Low

Read rates High Low

Privacy Issue Potential No

Material Type Performance affected Not affected

Total Cost of Ownership High Low

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Components of an RFID System

A RFID system is a set of components that work together to

capture, integrate, and utilize data and information. The

components are as follows according to [Brown 2007]:

Sensors

Tags

Antennas

Connectors

Cables

Readers

Networks

Controllers

Data

Software

Information Services

7

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Frequency Range – RFID applicationsLF HF Amateur Band UHF Microwave

Frequency 9 – 135kHz 13.553-

15.567 kHz

430-440MHz 860-930 MHz 2.4 – 2.4835 GHz

and 5.8 GHz

Typical

Applications

Aeronautical

/Marine

Communication

Smart Cards,

Personal

Identification

Baby Monitors,

amateur radio

Electronic Toll

collection (ERP)

Microwave ovens,

wireless network

RFID

Applications

Animal Tagging,

Access Control,

Vehicle

Immobilizers,

Speed pass

Access Control,

payment ID, item

level tagging,

luggage control,

biometrics, library

books, smart

shelves, apparel,

laundries,

pharmaceuticals

Active tags

identifying

containers,

vehicles

Supply Chain

(case and pallet

level), asset

management,

access control,

Baggage

tracking,

Anti-theft

protection

Security, access

control, work

tracking for factory

automation

Opaque

Materials

Not Susceptible Somewhat

Susceptible

Somewhat

Susceptible

Very Susceptible Very Susceptible

Performance

around liquid

and metal

Best Good Bad Bad Worst

Read rates Slow Slow Fast Fast Very Fast

Read range 20 inches 1 m 30m 4-5 m 10m

8

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RFID Readers (Interrogators)

RFID readers can be classified into whether they are stationary,

handheld or mounted.

9

Stationary Handheld Mounted/Mobile

Stationary readers are

usually mounted on a

wall, doorway, rest on

table or desktop. The

reader reads each tag

and store in a database.

Handheld readers are

used to locate items in a

distribution centre. They

are battery powered and

communicate over a

wireless connection to an

access point.

Mounted readers may be

attached to a forklift or

truck to record the

movement of goods from

one place to another.

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RFID Tags (Transponders)Type of tags Power Source Range Cost Type Lifetime

Passive Activated by

radio wave

from the reader

Transmit within

the field of

reader.

Up to 6m

Less

expensive.

About 5 cents

per tag when

purchased in

large quantity

Read or

Read/Write

Unlimited

Semi-active Battery-

assisted.

Battery is used

to run the chip

circuit

Transmit within

the field of

reader

Up to 100m

More

expensive.

Exceed $1 each

Read or

Read/Write

Limited Life

time (Battery)

Active Battery-

assisted.

Battery is used

to run the chip

circuit

Up to1000m Expensive Read or

Read/Write

Limited Life

time (Battery)

Chipless No integrated

circuits. Use

pattern to

encode data

Up to 30m Least

expensive

Read only Unlimited

10

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Radio frequency (RF) field:

Materials and effectMaterial Effect (s) on RF signal

Carbon Fibres 1. Absorption

Cardboard 1. Absorption (Moisture)

2. Detuning (dielectric)

Conductive liquid (e.g. shampoo) 1. Absorption

Group of cans 1. Complex effects (such as lenses, filters,

etc)

2. Reflection

Human body/Animals 1. Absorption

2. Detuning (dielectric)

Metals and Foil packaging Reflection

Glass Attenuation

Pastes Absorption

Plastics Detuning (dielectric)

11

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Electronic Product Code (EPC)

UPC (Universal Product Code) is limited because it contains only

manufacturer and product codes.

EPC is a code that is created and managed by EPCglobal

(http://www.epcglobalinc.org/). It identifies manufacturer, product

category, and individual item. It can be 8 to 32 characters, or 64 to 256

bits in length. EPC can store more information.

12

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The EPCglobal Network

There are 5 components of the

EPCglobal Network: EPC, ID

System, EPC Middleware,

Discovery Services, EPC

Information services (EPCIS)

The system starts with EPC stored

in RFID tag.

The EPC is a number that uniquely

identifies any item, and the scope of

the network is illustrated by the

scale of the EPC. E.g. at 96 bits, it

can uniquely identifies and track 296

items.

Such system requires components:

a standardized way to communicate

with reader, a way to filter relevant

items from data, way to create,

update, manage the database

13

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Logistics Processes Using EPCglobal

Network Standards The process repeated for

every product in the world, for

every step in the supply

chain, creates a treasure

cove of data that business

managers can use to :

authenticate products

determine accurate inbound

and outbound inventory loads

optimize logistics

prevent counterfeiting

prevent loss and theft

correct and control

misshipments

14

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RFID-enabled Integrated Distribution and

Light Manufacturing Facility (Illustration)

15

RFID-enabled handheld

terminals and/or material

handling equipment to

automatically track

inventory movement, verify

put-away and picklist and

update pick-list

Smart Shelf to automatically

update inventory

RFID Gantry to read and count incoming

and outgoing shipments. ASN, DO,

Manifest generation

RFID carts for WIP

and component

tracking

RFID Label printer for Slap-

Ship mandates

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Problem Statement Challenges associated order taking

Use of Handheld or PDA for order taking for Retail Sales and Logistics

Processes

Create searchable database involving Product ID, Description, Price, Discount

Schemes and Packing

Send orders directly to warehouse or allow handheld/PDA to sync with the

accounting system for invoice/picklist generation

Challenges associated with outgoing process

Make use of EPC standards for global unique identification

Use Class 1 Gen 2 Passive RFID tags (Write once, read many) on cartons or

products

RFID readers on gantry to read multiple cartons at once and match with

invoice/picklist information

Handheld RFID reader can be used to pick up the information of loose cartons

Note: Barcode does not support multiple reads although the cost is much

lower.

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Learning Outcomes

Discuss handheld applications for direct van and retail sales and

logistics

Compare different kinds of automated identification technology and

its applications

Compare RFID technology with Barcode (an established

technology)

Explain the suitability of RFID applications for different frequency

ranges

Evaluate the requirements of a RFID system – EPC process, EPC

tag data standard, RFID reader and RFID tags

SCHOOL OF ENGINEERING

P12 – Our Global Business

E223 : IT FOR SUPPLY CHAIN MANAGEMENT

Copyright © 2009 School of Engineering, Republic Polytechnic, Singapore

All rights reserved. No part of this document may be reproduced, stored in a retrieval

system, or transmitted, in any form or by any means, electronic, mechanical,

photocopying, recording or otherwise, without the prior permission of the School of

Engineering, Republic Polytechnic, Singapore.

Our Global Business Sam, Tony and John are three good friends. They are planning to set up a business to sell iPhone. As they have just graduated from Republic Polytechnic, they don’t have much savings. They want to reserve most of the capital on the products, instead of store rental and employees wages. All of them are in different countries now. Sam is in Singapore, Tony in Japan and John in the United States. To facilitate the order fulfillment process, three of them decided that access to customer order information anytime and anywhere is crucial to the business. They are seeking a cost effective solution to reach out to customers globally. Propose a suitable solution to them.

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P12

Our Global Business

E223 – IT for Supply Chain Management

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Connectivity

A connection, in the simplest terms, is a communication path.

Whenever you use the telephone you establish a connection, a

communication path between you and another person that

enables you to talk. You also establish a connection when you

use your browser to visit a Web site, or when you talk to

someone through instant messaging (IM/MSN) over the Internet.

A connection path is the pathway in which the data travels. It

can be through:

a wired connection such as using a network adapter (NIC card)

a dial-up modem

a wireless connection such as using a Wi-fi network

the internet

The client/server model is the most basic connectivity model.

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Internet, WWW and Internal

Corporate Network The internet is a global transmission network. It carries the

traffic of other networked applications such as email.

The Web (WWW) is a networked application that run over the

internet.

Internal corporate network connects computers within an

organization. Corporate networks support e-mail, the WWW, and

other personal productivity applications that you use on the

Internet. They also support organizational applications, such as

accounting, payroll, billing, inventory, and manufacturing.

Transaction processing applications are

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Nine elements of a network

Most networks share nine common elements. These elements

are applications (application programs), frames (messages),

client computers, server computers, switches, routers,

access lines, trunk lines, and wireless access points.

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Traditional Client/Server Architecture Client-Server model is the most

common IT system structure

traditionally. It enables different

clients to share common

information through central

server. The servers maintain

directory information, access

control, data, and most of the

important information.

When an end user wants to run

an application or retrieve data

from the shared database, the

client computers handle the initial

processing of the request. The

request is sent on to the server for

processing by the application

code, including data retrieval from

the shared database, as

necessary. The server returns the

results to the client PC where the

client is responsible for formatting

the screen display

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Internet Client/Server architecture In the internet client/server

architecture, PCs, the end-user

client computers, connect to the

Web server. The Web server,

though acting as a server, can

also be considered a client. It

connects to the database server,

passing end-user client requests

to the database and returning its

responses to the clients’ PCs.

Direct connections to a database

server over the Internet, though

possible, are rarely used. A

primary reason for this is the

potential security risk of directly

exposing a database server to the

Internet.

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Two-Tier Client/Server Architecture

It has only one client and one server. All communication takes place

on the internet between the client and the server.

The message that a web client sends to request a file or files from a

web server is called a request message.

When the server receive the request message, it executes the

command included in the message.

The server does this by retrieving the web page file from its disk and

then creating a properly formatted response message to send back to

the client.

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Three-tier (multi-tier) Architecture 3-tier architecture extends 2-tier architecture to allow additional

processing

E.g. catalog database & database management software and order

fulfillment & Payment processing system

The third-tier often includes databases and related software

applications that supply information to the web server. The web server

then use the output of these software applications when responding to

client requests, instead of just delivering a web page.

It is possible to have N-tier architectures

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Evolution of the Internet

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Interoperability - Web Services

A web service is a method

that is callable across the

internet

Web services allows you to

interconnect

Different companies

Many/any devices

Applications

Different types of clients

Support the distribution and

integration of applicator logic

Enable programmable

internet, not just interactive

internet

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Web Service Model

The Web Services model follows the publish, find, and bind paradigm

Web Service

Registry

Web Service

ProviderWeb Service

Client

Universal Description &

Discovery Integration (UDDI)

– provides mechanism for

client to find web services

Web Service Definition

Language (WSDL) – defines

services as a collection of

network endpoints or ports

Simple Object Access

Protocol (SOAP) – message

layout specification that

defines a uniform way of

passing XML coded data to

bind to HTTP as the

underlying communication

protocol 1. publish 2. find

3. bind/invoke

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Ensure the website is available to the

public There must be a fixed IP

address for the laptop

The server must have

internet address that is

public

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Benefits of Web Applications For

Supply Chain Management Collect information from production to delivery and share info for all

parties involved

Access data from single point of reference

Analyze, plan and make tradeoffs based on information along

entire supply chain

Flexible collaboration platforms with supply chain partners

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Collect information from production to

delivery and share info for all parties involved

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Access data from single point of reference

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Analyze, plan and make tradeoffs based on

information along entire supply chain

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Flexible collaboration platforms with supply

chain partners

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Problem Statement

– Web application (Google Sites)

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Problem Statement

– Online files sharing (Google Documents)

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Learning Outcomes

Describe connection, internet, WWW and elements of a network

Explain traditional and internet client/server architecture including 2-

tier, 3-tier and n-tier

Create a simple website and learn how to share the files online

Discuss the use of web applications and web services for supply

chain management

SCHOOL OF ENGINEERING

P13 –Greening the supply chain?

E223 : IT FOR SUPPLY CHAIN MANAGEMENT

Copyright © 2010 School of Engineering, Republic Polytechnic, Singapore

All rights reserved. No part of this document may be reproduced, stored in a retrieval

system, or transmitted, in any form or by any means, electronic, mechanical,

photocopying, recording or otherwise, without the prior permission of the School of

Engineering, Republic Polytechnic, Singapore.

Greening the supply chain The global environment is getting worse, more and more people start to think about what they can do to save our earth. Jonathan, the GM of Modus Logistics Ptd Ltd, is among them. Recently he read a very interesting article about green supply chain from http://greensupplychain.com/best_practices.html : “If you are like most businesses, the majority of the orders you send and receive are exchanged manually. For instance, AMR Research estimates only 20% of all orders in the retail supply chain are fully automated. Similarly, almost every other industry has limited automation when it comes to their supply chains…. But orders are just the tip of the iceberg. Ship notices, invoices and other business documents are too often manually managed transactions.” In fact, in Jonathan’s company, he is facing the same problem mentioned in the article. Jonathan is looking for a solution that can help the company reduce the manual transactions with their business partners.

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P13

Greening the supply chain

E223 – IT for Supply Chain Management

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Supply Chain Sustainability Role for

IT

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Sustainable Supply Chain

What is sustainable supply Chain?

A sustainable supply chain is a system of aligned business activities

throughout the lifecycle of products that creates value for all

stakeholders, ensures ongoing commercial success, and improves the

wellbeing of people and the environment.

~ Source: Business for Social Responsibility, 2007

Information technology offers a foundation that enables companies to

be accountable, to improve sustainable supply chain practices, and to

respond more proactively to external pressures while balancing

competitive realities within their industries

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How to improve on Supply Chain

sustainability and reduce carbon footprint? Automate Documentation to Reduce Your Paper Trail. Paper

documentation creates waste and places limitations on the work

process. Electronic documentation also vastly reduces the amount of

unnecessary paperwork throughout the supply chain process.

Create a Centralized Repository for Documentation. The storage

and centralization of documents gives staff the ability to access the

central database electronically to update, send and store documents

such as bills of lading, commercial invoices, packing lists and other

pertinent data as it moves through the automated company

documentation process.

Integrate Your Route Optimization and Consolidation Process. The

key to creating a greener supply chain lies in the exchange of all

documentation between you and your customers via an integrated

electronic data management system that permits automatic access to

files as they travel through the supply chain.

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How to improve on Supply Chain

sustainability and reduce carbon footprint? Create an Automated Storage and Archive System. Maintaining files

in an automated archive vastly reduces the amount of paperwork

involved in supply chain management process over a long period of

time, reduces the need for filing cabinets and frees up important floor

space.

Improve ROI by Greening Supply Chain Activities. Greening the

supply chain can be accomplished with a minimum of capital

investment and can improve the ROI of your customers, vendors and

company.

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EDI and B2B

Electronic data interchange, or EDI, is the Business-to-Business

(B2B) electronic exchange of business documents in a standard

format. In the EDI world, business documents are called

transaction sets, and the parties with which you exchange these

documents, such as your customers and suppliers, are referred

to as trading partners.

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EDI Standard

EDI standards describe the way an electronic business document

(e.g., a purchase order, an invoice) should be formatted. Defining

standards for an EDI purchase order, for instance, is similar to

defining the layout of a file that contains the purchase order data.

Standards define the document’s format, content, and data integrity

by specifying where the data is and what codes are accepted as

valid. This standardization enables a receiving computer to read and

validate the data because it knows exactly where to find everything.

For example, standards help trading partners determine where one

electronic document begins and ends, what type of document a

document is (e.g., a purchase order versus an invoice), and where

to find certain fields of information.

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EDI Envelopes

EDI envelopes are pairs of segments that enclose:

A series of segments that defines a transaction – Transaction Envelope

A group of transactions of the same type – Group Envelope

A number of groups destined for a particular trading partner – Interchange

Envelope

In EDI just about everything is a segment, but there are different

types of segments.

Elements represent a data value. A group of elements make up a segment.

A Transaction represents a business document such as a purchase order. A

transaction consists of multiple “element” segments. There is a segment that

indicates the start of a transaction, the “element” segments that make up the

data values of the transaction, and a segment indicating the end of a

transaction. Multiple group segments are put into an Interchange Envelope

segment.

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EDI Data Hierarchy - Interchanges

An EDI interchange is a collection of Groups or Transactions,

destined for one trading partner.

Hence, EDI Interchange ≡ EDI document ≡ EDI envelope.

Each interchange is enclosed in a pair of segments known as the

interchange envelope. For X.12, the group envelope is defined

by the ISA and IEA segment pair.

Separator characters are used to delimit elements and

components elements within a segment. E.g. ~ or *

Segment terminator is used to identify the end of a segment.

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EDI 856 Example

10

HL

PWK

TD1

TD5

TD3

TD4

REF

DTM

FOB

N1

N2

N3

N4

PER

SAC

CUR

V1

HL

REF

N1

N2

N3

N4

PER

HL

MEA

CLD

REF

MAN

HL

LIN

SN1

SLN

PRF

PID

MEA

PKG

REF

LH1

CUR

Envelopes Transactions Segments Elements

LIN01

LIN02

LIN03

LIN04

…

LIN31

AC

BP

DS

HD

LG

MD

PD

PL

UP

PN

VP DC193AZZ

PID01

PID02

PID03

PID04

PID05

F

Intel Pro 1000

MT Gigabit NIC

MEA01

MEA03

MEA04WT

KG

LB

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Message Transport

VANs (Value-Added Networks) are the most traditional and still

the most pervasive way to send and receive traditional EDI

documents. Other options include direct links, private or

proprietary networks, the Internet, and File Transfer Protocol

(FTP).

Your choice of transportation vehicle for EDI or XML transactions

will depend on how many trading partners and transactions you

have; your in- house technical expertise, security needs, and

budget; and several other factors.

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Message transport using same VAN

VANs offer many value-added

services, including translation of

data to EDI documents (and vice

versa), archiving, EDI to fax, and e-

mail. A VAN’s main function is to act

as the delivery agent of EDI mail.

Because each computer can use a

different transmission speed and

protocol, the VAN must convert

various speeds and protocols.

If you use a VAN for EDI exchange,

you don’t have to perform such

conversions. In addition, VANs act

as a security buffer by not permitting

your trading partners direct access

to your computer.

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Message transport using a Network

Gateway for different VANs The VAN of your choice often differs from your trading partner’s choice.

However, this situation isn’t a problem because most VANs can communicate

with each other. This capability, known as a gateway or interconnection, lets you

send your EDI mail to your VAN of choice.

In this scenario, your VAN sorts the mail and forwards any mail addressed to

trading partners on another VAN through to the appropriate VAN. Each trading

partner’s VAN then places the EDI documents in the appropriate mailbox.

However, some trading partners won’t accept an interconnection, requiring you

to maintain a mailbox on their VAN.

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Message transport over Internet using

AS2 protocol To accommodate EDI over the

internet, The EDI-INT group

subsequently created the

Applicability Statement 2 (AS2)

standards.

AS2 uses Hypertext Transport

Protocol (HTTP) and the added

security and synchronous transport

(for immediate delivery) that this

protocol offers. The use of AS2

protocol is known as EDI-INT. The

only connectivity required is direct

access to the Internet.

AS2 provides synchronous and real-

time transmission of the EDI

message as well as an immediate

message delivery notice.

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Markup languages

A markup language provides a way to combine a text and extra

information about it. The extra information, including structure,

layout, or other information, is expressed using markup, which is

typically intermingled with the primary text.

Example of markup languages are HTML, SGML and XML

XML is known as Extensible Markup Language. XML is

designed to fit where HTML was falling short (particularly

extensibility and reusability). XML was designed to describe

data and to focus on what data is.

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XML and the Enterprise application

XML (Extensible Markup Language) :

It enables information to be encoded with meaningful structure and in

a way that both computers and humans can understand.

It is excellent for information exchange, and is easily extended to

include user-specified and industry-specified tags.

XML’s specification is set by W3C: www.w3c.org

XML declaration in a document: Typically, a declaration is placed

on top of the XML file. The version attribute specifies the version

of XML document while the encoding attribute specifies the

character set coverage. By default, UTF-8 character set is

assumed.

E.g. <?xml version="1.0" encoding="ISO-8859-1"?>

<?xml version=“1.0” encoding=“UTF-8” ?>

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XML Syntax

A XML document contains: Element, Tags and Text:

Element

<City> Singapore </City>

Tag Text Tag

An XML document must have a root tag to describe it:

<Address>… …

</Address>

All elements must have a Start and End Tag

<City>Singapore</City>

If the text or item is null for some reason, it can be represented using

empty XML element: E.g. <Age/>

Attribute values must always be quoted. E.g. <order id =“OD111”>

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XML elements naming conventions

Naming conventions for elements

Elements names must start with a letter from alphabet or and

underscore “_”. Note: you cannot have element name with special

characters or start with number (but can have number within) or

spaces. E.g. illegal naming: <#beta>, <987town>

Elements names cannot contain spaces.

E.g. illegal naming: <grocery list>, accepted: <grocery_list>

Element names cannot start with the word XML.

E.g. illegal naming: <xml>, <XML>, <XML_item>

After < or </, you cannot have a space first but can have a space

trailing the element name.

E.g. illegal naming: < Item1>, accepted naming: <item1 >

Element name is case sensitive: E.g. <CAR> and <car> are different

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XML Text Text Length: any length as deem necessary.

Content: It can contains anything from binary code, image or other

document

Spoken languages: It can contain any spoken languages.

E.g. <Message>这是中文文件</Message>

Whitespace: It refers to space, line feed, tabs, and carriage return within

the XML document. All the whitespace are preserved.

Entity references: Some characters cannot be contained as a value within

an XML element and encoding is required:

19

Character Entity

< &lt;

> &gt;

“ &quot;

„ &apos;

& &amp;

Tom & Jerry must be

encoded as

Tom &amp; Jerry in

the XML document

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EDI v.s XML

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XML Enabled EDI

21

Easy translation from XML to standardized EDI or visa versa

Lower cost

Easy on-ramp to work with major EDI enabled players

Allow non-EDI enabled SMEs to trade with EDI enabled

organizations

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A well-formed XML

22

Sales orders sorted

by Transaction date:

A XML that follows the rules as indicated by is a well-formed

XML. It means that the XML elements are properly written and

following the rules of XML.

Tree view representation of XML

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Alternative XML

23

Sales orders sorted

by Product Name:

Tree view representation of XML

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Validation in XML Document using

DTDs If you plan to share information or services using an XML document

between two processes, applications, or other entities, you must put in

place a set of rules that define the structure of the XML document to be

passed.

DTD (Document Type Definition) is used to validate XML. It can be

stored in the same XML file that it defines (called inline DTD) or it can

be held in separate files (called external DTD with .dtd extension).

The best practice is to reference an external DTD from XML file. This

enables the separation between data (XML) and data definition (DTD).

A "Valid" XML document is a "Well Formed" XML document, which

also conforms to the rules of a Document Type Definition (DTD).

Other benefits using with a DTD is that, independent groups of people

can agree to use a standard DTD for interchanging data. This also

ensures the consistency of the XML.

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Validate XML Document

25

Modify the XML file according to the error description to make it well-

formatted.

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Problem Statement

To reduce paper document, Jonathan should automate the

documentation.

Jonathan can consider to use EDI with major business partners.

For those SME partners who don’t have EDI, Jonathan can use

EDI/XLM tools to convert the EDI files to the more readable XML files.

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Learning Outcomes

Discuss Sustainable Supply Chain through IT adoption

Discuss integration approach in enterprise application using EDI

X.12 and perform data mapping

Explain message transport mechanism in EDI using VAN or Internet

using AS2

Discuss integration approach in enterprise application using XML

Construct a valid XML document to represent the data for

information exchange and explain the use of DTD (Document Type

Definition)

Compare EDI and XML.

SCHOOL OF ENGINEERING

P14 – A Sound Estimate

E223 : IT FOR SUPPLY CHAIN MANAGEMENT

Copyright © 2010 School of Engineering, Republic Polytechnic, Singapore

All rights reserved. No part of this document may be reproduced, stored in a retrieval

system, or transmitted, in any form or by any means, electronic, mechanical,

photocopying, recording or otherwise, without the prior permission of the School of

Engineering, Republic Polytechnic, Singapore.

A Sound Estimate Xu Ting works in Transland Logistics services, a company which provides transportation services which include local, export and import delivery within Singapore. Currently, there is no efficient way to keep track of assets being used by staff in the operations department. Examples of items loaned are PDAs, handheld RFID devices and barcode readers. Very often, items may be lost or damaged and usage unaccounted for. There is no way to trace who has borrowed and used the items. In view of this, the management decided to embark on an information systems development project so that there can be a centralise control of the items borrowed. The project is named “Asset Management Systems Development Project”. It consists of four main tasks namely: Concept, Application Design, Application Development and Roll-out. The budget it has set aside is $500,000 and the project is expected to be completed within 1 year. The application development team in the Information Systems (IS) department would be assigned to the project. There are one application development manager, two development engineers and 1 project analyst in the team. The requirements for the project have been determined and you are given the project scope. Your challenge today is to help her develop a detail WBS and responsibility assignment matrix. A cost estimate of the labor would be useful too. State any assumptions.

Asset Management Systems Development Project Project Scope Statement

Project Description:

Currently, the company has different type of assets to keep track and manage. It

ranges from PDAs, handheld RFID devices to barcode readers. Proper tracking

and management of asset help in planning asset replenishment and prioritization

of purchase (e.g. end-of-life). It also provides useful information on existing asset

such as whether they have been repaired or replaced. Any preventive or

replacement costs can be tagged to the asset. Project Objectives: This project aims to develop a simple asset management system to manage the current asset in the company. The project team must release the project in 1 year’s time. Project Deliverables: The deliverables for the project are: 1. Requirement Specifications – User and Systems 2. Design Specifications – Functionality, application development approach,

application development tools 3. Asset Management System

a. Application Design – Design the database, user logon, forms and menus and reports

b. Application development – Create database, develop logon, develop database, develop functionalities for forms and menus, linkage of SQL to reports

4. Roll out – User manual, User Acceptance Test, conduct a pilot run Initial Project Organisation: The team will start with a one application development manager, two development engineers and 1 project analyst.

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P14

A Sound Estimate

E223 – IT For Supply Chain Management

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Project and Project Management

2

A project is “a temporary endeavor undertaken to create a unique product, service, or

result.”. The following are the important project characteristics:

a. It is temporary: means that every project has a definite beginning and end. It does

not mean short in duration.

b. A project creates a unique product, service or result. Uniqueness is an

important characteristics of project deliverables. E.g. unique location, different

design, different contractors, different owners, etc.

c. It has progressive elaboration. It means that it develops in steps and progress

with increments.

A project ends when its objectives have been reached, or the project has been

terminated because objectives cannot be met or when the needs of the project no

longer exist. Projects can be large or small and take a short or long time to complete.

Project management is “the application of knowledge, skills, tools and techniques to

project activities to meet project requirements.”

Project management tools and techniques assist project managers and their teams in

various aspects of project management.

Specific tools and techniques include: Project charters, scope statements, and WBS

(scope), Gantt charts, network diagrams, critical path analyses, Cost estimates and

earned value management (cost).

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Project Management Managing a project typically includes:

Identifying requirements

Addressing the various needs, concerns and expectations of the

stakeholders as the project is planned and carried out

Balancing the competing constraints including

Scope

Quality

Schedule

Budget

Resources

Risk

The specific project would influence the constraints the project manager need to

focus. E.g. if a schedule is shortened, often a budget needs to be increased to

add additional resources to complete the same amount of work in less time.

A successful project is one that meets or exceeds the expectation of the

stakeholders. E.g. of stakeholders: Project Sponsor, Customer, Suppliers,

Board of Directors, Project manager.

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Project Management Vs Operations

Management Operations are an organizational function performing the ongoing

execution of activities that provide a repetitive service or produce

the same product. E.g. logistics, warehousing, production or

manufacturing operations.

Operations require business process management or operations

management.

Operations are permanent endeavors that produce repetitive

outputs, with resources assigned to do basically the same set of tasks.

Project are temporary endeavors. Though temporary in nature, it can

help to achieve organizational goals when they are aligned with

organization’s strategy.

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Example of IT Project Upgrade/Enhancement

A small software development team adds a new feature to an internal

software application.

A help desk or technical worker replaces laptops for a small department.

A college campus upgrades its technology infrastructure to provide wireless

Internet access.

Purchase with implementation

A cross-functional task force in a company decides what software to

purchase and how it will be implemented.

Application Development

A television network develops a system to allow viewers to vote for

contestants and provide other feedback on programs.

A government group develops a system to track child immunizations.

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Project Life Cycle and IT Development The project life cycle is a collection of logical stages or phases that

maps the life of a project from its beginning to its end in order to define,

build and deliver the product of a project – information system.

6

Implementation

Planning

AnalysisDesign

SDLC

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Project Scope Management

Scope refers to all the work involved in creating the products of the

project and the processes used to create them

A deliverable is a product produced as part of a project, such as

hardware or software, planning documents, or meeting minutes

Project scope management includes the processes involved in

defining and controlling what is or is not included in a project

7

Project Scope Management

Collect Requirements

Define Scope Create WBS

WBSWBS

DictionaryScope

Baseline

Project Document updates

Verify ScopeControl Scope Processes

Outputs

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Work Breakdown Structure(WBS)

What is the secret behind accomplishing seemingly impossible

tasks in any area? The answer is to break down the required

work into smaller, manageable pieces. This is also a very

important process in project management.

To be able to actually execute the project, the project scope is

broken down into manageable tasks by creating a work

breakdown structure (WBS).

A WBS is a deliverable-oriented hierarchy of the work that must

be performed to accomplish the objectives and create the

deliverables for the project.

Throughout the project, the WBS works as a reference for

communication regarding what is included in the project and

what is not.

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WBS – Mind Mapping Approach

Mind mapping is a technique that uses branches radiating out

from a core idea to structure thoughts and ideas In mind mapping

approach, we write tasks in a non-linear, branching format and

then create the WBS structure.

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WBS – From Mind map to WBS

(Illustration)

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WBS – Top-down approach

(Decomposition technique) Decomposition is a technique for subdividing the project

deliverables into smaller, manageable tasks called work

packages.

The WBS is a hierarchical structure with work packages at the

lowest level of each branch. Based on their complexity, different

deliverables can have different levels of decomposition.

Below shows a first level decomposition of the project:

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WBS – Further decomposition I

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Further decomposition

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WBS – Further decomposition II

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Further decomposition

- Sub levels created

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WBS Dictionary

A WBS dictionary is a supporting document that provides the

details of the component of the WBS. Below shows an entry of a

WBS dictionary.

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WBS Dictionary Entry, 10-Jan-2010

Project Title: Asset Management Systems Development Project

WBS Item Number: 1.4

WBS Item Name: Define application development approach

Description: The IS department has standardized certain IT development

tools for software development purpose. This task involve detail analysis of

the current project requirement: both user and systems requirement and

decide whether the current software development tool is adequate.

Application functionalities and software development approach must also

be taken into consideration. Completing this task is dependent on WBS

item number 1.1, 1.2 and 1.3.

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Processes based on WBS

The WBS is at the heart of project management. It affects

directly or indirectly almost all the processes that are performed

after its creation. Below are some of the processes that are

based on the WBS.

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WBS

Cost Estimate

Human Resource Planning

Risk Management

Planning

Quality Planning

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Human Resource Plan

It Involves identifying and documenting project roles, responsibilities,and reporting relationships

Outputs include:

Project organizational charts

Staffing management plan

Responsibility assignment matrixes

Resource histograms

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Project Organisational chart

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Development Manager

Project Analyst

Development Engineer 1

Development Engineer 2

Current Project organizational Chart

A big project

organizational Chart

Traditional organization chart structure can be used to show the positions and

relationships in a graphic top-down format.

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Responsibility Assignment Matrix

A responsibility assignment matrix (RAM) is a matrix that maps the

work of the project as described in the WBS to the people responsible

for performing the work. One example is the RACI chart.

R = responsibility, only one R per task

A = accountability

C = consultation

I = informed

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Development

Manager

Development

Engineer 1

Development

Engineer 2

Project

Analyst

Prepare User Manual I C A R

Prepare User Acceptance Test I R C A

Prepare Pilot Run I A R C

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Project Cost Estimates

Project cost management includes the processes required to ensure

that the project is completed within an approved budget. There are

three project cost management processes:

Cost estimating: developing an approximation or estimate of the

costs of the resources needed to complete a project

Cost budgeting: allocating the overall cost estimate to individual

work items to establish a baseline for measuring performance

Cost control: controlling changes to the project budget

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Cost

Estimate

for

Labor

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Going Further

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Create ERD for the database

Define Datatypes

Design report layout

Design SQL

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Problem Statement

It is important to understand the nature of a project: temporary nature,

unique, has a definite start and end and independent of the duration

and size.

A Project life cycle consists of starting the project, organizing and

preparing, carry out the work and closing the project.

There are different type of IT project such as upgrades/Enhancement,

Purchase with implementation and application development.

After the requirements is collected and project scope specified (in the

form of project scope statement), WBS and WBS dictionary are created.

A WBS can be created using mind-mapping or decomposition

technique.

Human resource plan is also important for a project such as

organisation chart and RACI matrix.

Project cost management helps a company in cost estimates,

budgeting and cost control.

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Learning Outcomes

Create a detail WBS for an ICT project using decomposition

technique

Create a Responsibility Assignment Matrix for the ICT project

Construct a project cost estimate of the items in the WBS

SCHOOL OF ENGINEERING

P15 –

Getting it done on time!

E223 : IT FOR SUPPLY CHAIN MANAGEMENT

Copyright © 2010 School of Engineering, Republic Polytechnic, Singapore

All rights reserved. No part of this document may be reproduced, stored in a retrieval

system, or transmitted, in any form or by any means, electronic, mechanical,

photocopying, recording or otherwise, without the prior permission of the School of

Engineering, Republic Polytechnic, Singapore.

Getting it done on time! As the Project Manager in charge of the development of the Asset Management Systems for your client, you have finalized the Work Breakdown Structure (WBS) as shown in the chart below.

You have also worked out the duration for each of the task based on your available resources, as well as the predecessor for each task. How can you illustrate the sequencing, relationships as well as the schedule of the tasks in order to help you in managing the project deadline?

Task Duration Predecessor

1.0 Depends on when all subtasks are completed

1.1 Depends on when all subtasks are completed

1.1.1 7 days

1.1.2 8 days

1.2 7 days 1.1

1.3 5 days 1.2

1.4 5 days 1.3

2.0 Depends on when all subtasks are completed 1.0

2.1 20 days

2.2 10 days 2.1

2.3 14 days 2.2

2.4 * 13 days 2.3

3.0 Depends on when all subtasks are completed

3.1 Depends on when all subtasks are completed 2.1

3.1.1 24 days

3.1.2 36 days

3.2 35 days 2.2

3.3 * 80 days 2.3

3.4 70 days 2.4 and 3.3

4.0 Depends on when all subtasks are completed 3.0

4.1 44 days

4.2 45 days

4.3 30 days 4.1, 4.2

Note: * indicates milestones Your client wants to know the duration of the project, and as per the demand of all customers, they want to shorten this duration.How do you propose to do so?

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P15

Getting it done on time!

E223 – IT for Supply Chain Management

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Importance of Project Schedules

Managers often cite delivering projects on time as one oftheir biggest challenges

Schedule issues are the main reason for conflicts onprojects, especially during the second half of projects.

Time has the least amount of flexibility; it passes nomatter what happens on a project.

Individual work styles and cultural differences also causeschedule conflicts as some people prefer to followschedule and deadlines while others do not

Different cultures and even entire countries havedifferent attitudes about schedules

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Project Time Management Process

Activity definition: Identifying the specific activities that the project team members and stakeholders must perform to produce the project deliverables.

Activity sequencing: Identifying and documenting the relationships between project activities.

Activity resource estimating: Estimating how many resources a project team should use to perform project activities.

Activity duration estimating: Estimating the number of work periods that are needed to complete individual activities.

Schedule development: Analyzing activity sequences, activity resource estimates, and activity duration estimates to create the project schedule.

Schedule control: Controlling and managing changes to the project schedule.

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Milestones

A milestone is a significant event that normally has no duration, but

can also be used to mark a task of any duration

It often takes several activities and a lot of work to complete a

milestone.

Milestones are useful tools for setting schedule goals and monitoring

progress.

Examples include completion and customer sign-off on key

documents and completion of specific products

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Activity Sequencing

Involves reviewing activities and determining dependencies.

A dependency or relationship relates to the sequencing of project

activities or tasks.

You must determine dependencies in order to use critical path

analysis.

Network diagrams are the preferred technique for showing activity

sequencing.

A network diagram is a schematic display of the logical

relationships among, or sequencing of, project activities.

Two main formats are the Arrow Diagramming Method (ADM) and

Precedence Diagramming Method (PDM)

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Precedence Diagramming Method (PDM)

Activities are represented by boxes.

Arrows show relationships between activities.

More popular than ADM method and used by

project management software.

Better at showing different types of dependencies.

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Task Dependency Types

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Sample PDM Network Diagram

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Arrow Diagramming Method (ADM)

Also called activity-on-arrow (AOA) network diagram.

Activities are represented by arrows.

Nodes or circles are the starting and ending points of activities.

Can only show finish-to-start dependencies.

Sample ADM Network Diagram

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Scheduling Development

Uses results of the other time management processes to determine

the start and end dates of the project.

Ultimate goal is to create a realistic project schedule that provides a

basis for monitoring project progress for the time dimension of the

project.

Important tools and techniques include Gantt charts, critical path

analysis, critical chain scheduling, and PERT analysis

There can be 2 types of scheduling strategies:

Forward scheduling – a project scheduling approach that establishes a project

start date and then schedules forward from that date.

Reverse scheduling – a project scheduling strategy that establishes a project

deadline and then schedules backward from that date.

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Gantt Charts

Gantt charts provide a standard format for

displaying project schedule information by listing

project activities and their corresponding start

and finish dates in a calendar format.

Symbols include:

Black diamonds: Milestones

Thick black bars: Summary tasks

Lighter horizontal bars: Durations of tasks

Arrows: Dependencies between tasks

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Example of Gantt Chart

Test

Test

Test

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Critical Path Method (CPM)

CPM is a network diagramming technique used to predict total

project duration.

A critical path for a project is the series of activities that determines

the earliest time by which the project can be completed.

The critical path is the longest path through the network diagram and

has the least amount of slack or float.

Slack or float is the amount of time an activity can be delayed

without delaying a succeeding activity or the project finish date.

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Calculating the Critical Path

Develop a good network diagram.

Add the duration estimates for all activities on each path through

the network diagram.

The longest path is the critical path.

If one or more of the activities on the critical path takes longer than

planned, the whole project schedule will slip unless the project manager takes corrective action

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Using the Critical Path to shorten a

Project Schedule Three main techniques for shortening schedules:

Shortening the duration of critical activities or tasks by adding more

resources or changing their scope.

Crashing activities by obtaining the greatest amount of schedule

compression for the least incremental cost. It is a compression

technique that looks at cost and schedule trade-offs. One of the

things you might do to crash the schedule is add resources, from

either inside/outside the organization to the critical path tasks.

Fast tracking activities by doing them in parallel or overlapping

them. This is a technique where 2 activities that were previously

scheduled to start sequentially, start at the same time.

Note: It is important to update project schedule information to meet time

goals for a project, as the critical path may change

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Schedule Control

Goals are used to know the status of the schedule,

influence factors that cause schedule changes,

determine that the schedule has changed, and manage

changes when they occur.

Tools and techniques include:

Progress reports.

A schedule change control system.

Project management software, including schedule comparison

charts, such as the tracking Gantt chart.

Variance analysis, such as analyzing float or slack.

Performance management, such as earned value

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Problem Statement – Gantt Chart

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Problem Statement – Compare Gantt

Chart and Tracking Gantt

Critical path

(as shown in red)

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Problem Statement – Critical Path

(Shown in Tracking Gantt)

Critical path (as shown in red in TrackingGantt) is1.1.2 -> 1.2 -> 1.3 -> 1.4 -> 2.1 -> 2.2 -> 2.3 ->3.3 ->3.4 -> 4.2 -> 4.3

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Problem Statement Tasks in critical path

Tasks that has free slack

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Problem Statement

Total duration takes 294 days to complete

The duration can be shortened by

Shortening the duration of critical activities or tasks by adding

more resources, such as adding in more staff to complete the

tasks along the critical path, e.g. 2.3, 3.4

Crashing activities by obtaining the greatest amount of schedule

compression for the least incremental cost.

Fast tracking activities by doing them in parallel or overlapping

them.

The tasks that contain slack are 1.1.1, 2.4, 3.1.1, 3.1.2, 3.2 and4.1; these tasks can be slightly delayed by allocating resourcesthat are initially for these tasks to focus on the critical tasks

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Learning Outcomes

Explain the project time management process

Illustrate activity sequencing using network diagrams (AOA)

method

Illustrate activity sequencing using precedence diagramming

method (PDM)

Create Gantt chart for displaying project scheduling information