stud-01-nature of information systems

8/4/2019 Stud-01-Nature of Information Systems

1/53

Lecture 1: Nature of Information Systems SYSADES/SYSANAL/INSYSTE

01-1

1

Lecture 01:Lecture 01:

Nature of Information SystemsNature of Information Systems

SYSADES/SYSANAL/INSYSTE

Professor: SAD Team


2/53


01-2

Lecture 01:Nature of Information Systems 22SYSADES/SYSANAL/INSYSTE

Overall Picture (1/3)Overall Picture (1/3)

Nature ofNature ofInformation SystemsInformation Systems

L1L1

TheTheSystemsSystemsAnalystAnalyst

L2L2

Types ofTypes ofInformationInformation

SystemsSystems

L3L3

SystemsSystemsDevelopmentDevelopment

Life CycleLife Cycle

L4L4

DataData

GatheringGatheringMethodsMethods

L5L5


3/53


01-3



Analysis of System NeedsAnalysis of System NeedsL6L6

SADSAD

MethodologiesMethodologiesand Frameworksand Frameworks

L10L10

Systems ProposalSystems ProposalL9L9

Abstract ModelAbstract Modelof the Systemof the System

L8L8RationalRationalUnifiedUnifiedProcessProcess

L7L7


4/53


01-4



Systems Concepts and Fundamentals:

J Lecture 1: Nature of I nformation Systems Lecture 2: The Systems Analyst

Lecture 3: Types of Information SystemsLecture 4: Systems Development Life Cycle (SDLC)

Lecture 5: Data Gathering MethodsLecture 6: Analysis of System Needs

Lecture 7: Basics of Rational Unified Process

Lecture 8: Abstract Model of the SystemLecture 9: Systems ProposalLecture 10: SAD Methodologies and Frameworks


5/53


01-5


Learning ObjectivesLearning Objectives

1. To describe the value of information, being a

processed data.2. To define information systems analysis and

design.3. To explain the concept of a system.4. To differentiate the nine characteristics of a

system.5. To examine the components of information

systems.6. To compare manual and computer-based

information systems.

7. To distinguish the roles of variousinformation system personnel.


6/53


01-6


Lecture OutlineLecture Outline

1. Value of Information

2. Role of SAD

3. Concept of a System

4. Nine Characteristics of a System

5. Components of Information Systems

6. Manual and Computer-BasedInformation Systems

7. Information System Personnel Roles

8. Summary


7/53


01-7


WhatWhats Next?s Next?

1.1. Value of InformationValue of Information

2. Role of SAD






8. Summary


8/53


01-8


Value of InformationValue of Information

The key to successkey to success in business isthe ability to gather, organizeand interpret information.

[Hoffer et al, 2004]


9/53


01-9


Data vs. InformationData vs. Information

Data is a collection of facts. Information is processed, stored

or transmitted data.


10/53


01-10


Why is Information Important?Why is Information Important?

It is an organizational resourcethat serves as a tool fordecision-making.

[Kendall & Kendall, 2002]

Cost is associated with information processing. Information processing must be managed to take full advantage of its

potential.


11/53


01-11




2.2. Role of SADRole of SAD






8. Summary


12/53


01-12


What is the Role of SAD?What is the Role of SAD?

Systems Analysis and Design (SAD)lays the foundation for understandingthe framework to be implemented.

[Wasson, 2005] System development requires more than simply implementing a

standard framework. Understanding the framework requires understanding of:

WHAT systems are

HOW the user envisions deploying, operating, supporting, anddisposing of the system

WHAT conditions and WHAT outcomes are users expected toachieve


13/53


01-13


What is SAD? (1/4)What is SAD? (1/4)

BUILD

SAD

DESIGNANALYSIS

Oftentimes, SAD results to the creation of an application software: acomputer software designed to support organizational functions or

business processes.


14/53


01-14



Analysis Establishes the understanding of an

existing system and what is requiredfrom it.

Outputs:

System description

Set of requirements for the new system


15/53


01-15



Design The phase that proposes the new

system which meets the requirementsspecified under the analysis stage.

Output:

System architecture


16/53


01-16



Build The phase used to develop the system

once the design has been approved.

Output:

Developed system


17/53


01-17




2. Role of SAD

3.3. Concept of a SystemConcept of a System





8. Summary


18/53


01-18


What is a System?What is a System?

An inter-related andinterdependent set ofcomponents:With an identifiable boundary

Interfacing one another to achieve oneor more predefined goals.

Components may be people, equipment and procedures, etc. Since all systems are inter-related and interdependent, when one

element of a system is changed or eliminated, the rest of the systemscomponents (elements and subsystems) are also impacted.


19/53


01-19


What is a Boundary?What is a Boundary?

A line that marks the inside andoutside of a system Sets off the system from its

environment

The conceptual boundary includes or considers the following: All components of the system.

That which provides input to the system. That which is influenced by the output from the system.


20/53


01-20


Main Types of SystemsMain Types of Systems

Closed Systems Those that are not influenced

by and do not interact withtheir environment.

Open Systems Interact with and are effected

by their external environment.

Closed Systems: Mostly mechanical and have necessary predetermined motions or

activities that must be performed regardless of the environment.

Open Systems:

Affected by the external environment that includes social, political,legal, technological and economic forces.


21/53


01-21


Organizations as SystemsOrganizations as Systems

Organizations are complexsystems with departments orbusiness units linked bypeople working together.

Organizations use feedbackas aform of system control to monitor

performance.

The organization as a system should be defined by the relationshipamong human beings and the its purpose, rather than by the

machines and facilities that it uses.

The boundaries of an organization define its inputs and outputs.

Inputs may include raw materials, forms and even people (in the formof labor) entering the system to be processed into outputs (such as

finished products and sales) that are useful to the organization.

As the organization interacts with various elements in its environment,

feedback is important, especially for managers making decisions in achanging environment.


22/53


01-22


Organizations as SystemsOrganizations as Systems

Business Units Business Units

Business Units

ENVIRONMENT

Feedback

Boundary

Monitoring

A theoretical view of systems

ORGANIZATION


23/53


01-23




2. Role of SAD


4.4. Nine Characteristics of a SystemNine Characteristics of a System




8. Summary


24/53


01-24


Nine Characteristics of a SystemNine Characteristics of a System

1. Purpose the overall goal orfunction of a system

2. Boundary the line thatmarks the inside and outside ofa system and that sets thesystems from the environment


25/53


01-25



3. Component either anirreducible part or an aggregateof parts, also called subsystem

4. Interrelated componentsdependence of one subsystemon one or more subsystems


26/53


01-26



5. Input whatever the systemtakes from its environment inorder to fulfill its purpose

6. Output whatever the systemreturns to its environment inorder to fulfill its purpose


27/53


01-27



7. Interface point of contactwhere a system meets itsenvironment or wheresubsystem meets each other


28/53


01-28



8. Environment everythingexternal to a system thatinteracts with the system

9. Constraint a limit to what asystem can accomplish


29/53


01-29


How to Analyze a SystemHow to Analyze a System

1. Define the purpose.2. Identify the system boundary.

3. Define the system components.

4. Specify the relationships amongcomponents.


30/53


01-30


How to Analyze a SystemHow to Analyze a System

5. Define IPO (Input-Process-Output).

6. Specify the interfaces.

7. Determine theenvironmental factorsand constraints.


31/53


01-31


McDonaldMcDonalds as a Systems as a System

Storage Office

Kitchen

Counter

Eating

Area

Inputs:

Ingredients,labor, cash,

etc.

Outputs:

Preparedfood, cash

sales,trash, etc.

Boundary

Environment: customers, food distributors, banks, etc.

InterfaceInterface

Components

1. Purpose : to make profit for the owners2. Boundary: physical walls of the restaurant

3. Components: storage, office, kitchen, counter, eating area4. Interrelatedness: all components work together to prepare the food

to deliver to customers

5. Input: ingredients, cash and labor6. Output: prepared food, cash sales, trash

7. Interfaces: storage-to-kitchen door, for preparation of supplies;kitchen-to-counter window, for sending prepared food; counter-table,for ordering by customers; back door, for deliveries of supplies from

food distributors; other communication facilities8. Constraints: prepares only easy fast-food, location, and government

regulation

9. Environment: customers, food distributors, financial institutions,competitors


32/53


01-32




2. Role of SAD



5.5. Components of Information SystemsComponents of Information Systems



8. Summary


33/53


01-33


What is an Information System? (1/2)What is an Information System? (1/2)

A collection of procedures, programs,equipment and methods,

Processing data into information, and

Making information available todecision-makers.

**Remember the concept ofI PO(Input -Process-Output)throughout this course.

[Laudon & Laudon, 2003] From a business perspective, an information system is an

organizational and management SOLUTION, based on informationtechnology, to a challenge posed by the environment.


34/53


01-34


What is an Information System? (2/2)What is an Information System? (2/2)

combine

to create

that provide

Information SystemsInformation Systems

INPUT:

ddaattaa

hardware

software

peopleprocedures

PROCESS: data processing

informationOUTPUT:


35/53


01-35


Components of Information SystemsComponents of Information Systems

Strategy

BusinessProcesses

andProcedures

People

Technology

Integration

All components of Information Systems (IS) must be properlyintegrated to enable successful processing of data into valuable

information. The organization (as an information system) must initially define its

overall strategy to identify the key people needed to execute this

strategy for the success of the organization. People make use of technology to work on the organizations

business processes and procedures. Business processes and procedures allow the realization of the

organizations strategy.


36/53


01-36



Strategy game-plan of theenterprise used to achieve itsvision-mission

People an essential element,as information are producedand used by people.


37/53


01-37



Technology/Equipment theenabler or means to store andprocess data into information.

Business Process/Procedurespecifies what is to be donewith data as it enters and

passes through the system.

Business processes and procedures also ensure that information arebeing received by the right people at the right time.


38/53


01-38




2. Role of SAD




6.6. Manual and ComputerManual and Computer--BasedBasedInformation SystemsInformation Systems


8. Summary


39/53


01-39


Manual Information SystemsManual Information Systems

Use formalized procedures, notcomputer based, for production ofinformation within an organization

Still widely used due to: Unwillingness to invest in new technology

Lower development costs

Staff expertise

Prior to computers, all organizational information systems areoperated in this way.


40/53


01-40


ComputerComputer--Based Information Systems (CBIS)Based Information Systems (CBIS)

Utilizes information technology andcomputers to provide data processingand/or information for decisionmakers

Main Benefits: Faster data processing

Higher productivity


41/53


01-41




2. Role of SAD





7.7. Information System Personnel RolesInformation System Personnel Roles

8. Summary


42/53


01-42


Information System Personnel RolesInformation System Personnel Roles

1. Business Managers Functional department heads andcorporate executives.

Allocate necessary resources for the

projects success.

Set general requirements, direction andconstraints for development project.

Business managers also provide funding for the development of theproject.

They have decision-making authority and knowledge of the firms linesof business. At the same time, they can also propose and approveprojects.


43/53


01-43



2. IS Managers Oversee the approved systemdevelopment projects.

Prescribe the methodologies, techniques

and tools to be used.

Responsible for solving the problemsarising during project development.

The IS Managers are also responsible for career planning anddevelopment for systems analysts and other employees.


44/53


01-44



3. Systems Analysts Key individuals in the systemsdevelopment process.

Systematically assess how businessesfunction.

Involved in every phase ofdevelopment.

The role of the system analysts will be discussed further in Lecture 2.


45/53


01-45



4. Programmers / SoftwareDevelopers Convert the system specifications

given to them by analysts into

instructions that the computer canunderstand.


46/53


01-46



5. Technicians/Specialists Database Administrator

Network and TelecommunicationsExperts

Human Factors Specialists

Internal Auditors

Database Administrator - involved in design, development andmaintenance of databases.

Network and Telecommunications Experts - develop systemsinvolving data and/or voice communications.

Human Factors Specialists - involved in training users and writing

documentation. Internal Auditors - ensure that required controls are built into the

system.


47/53


01-47



6. End-User Developers Users who cannot wait longer to get

their systems, thus creating a systemon their own.

Use high-level software andlanguages such as electronicspreadsheets and RDBMS.

RDBMS Relational Database Management System


48/53


01-48



7. End Users The actual users of the information

system (being) developed.

Provide the information andspecifications for the development ofthe information system.


49/53


01-49




2. Role of SAD






8.8. SummarySummary


50/53


01-50


Summary (1/3)Summary (1/3)

Information is a processeddata that serves as a keyresource in organizations fordecision-making.

SAD lays the foundation forunderstanding the frameworkto be implemented.


51/53


01-51



Asystem is an inter-related and

interdependent set of components thatachieve predefined goals and with anidentifiable boundary.

Information systems process datainto information by integrating strategy,people, technology and businessprocesses.


52/53


01-52



CBIS utilizes informationtechnology and computers tospeed up processing andincrease productivity.

Various IS personnel performspecific roles to ensure thesuccess of organizations.

CBIS: Computer-Based Information System IS: Information System


53/53

stud-01-nature of information systems

Documents