MIS JUMP START!

http://www.youtube.com/watch?v=cL9Wu2kWwSY

MIS 111: COMPUTERS AND

THE INTER-NETWORKED

SOCIETYClass 14: Systems Analysis and

DesignJuly 30th, 2009

ADMINSITRATION Check your grades

Correct?Absences

Final Quizzes Course evaluation

Handing back assignments Assignment 4 starts today, is due

Thursday We are having a party!! Next Tuesday!

Giraffe

LEARNING OBJECTIVES List a few current events in information

systems news Compare and contrast four methods for

systems analysis and design Explain what happens in the planning stage Explain why it is important to understand

company culture Specify requirements by using an event table Create a context diagram Create DFD fragments Create a decision tree

INFORMATION SYSTEMS SOLUTIONS

Buy off-the-shelf products It’s rare that a single software package

serves all of the company’s needs (and future needs!)

Lease the ApplicationsBetter for small to medium-sized companies

that might not have the $ to invest in an off-the-shelf product

Use Open Source SoftwareQuality can be suspect, even though it’s

free… What else is there?

DEVELOPING APPLICATIONS IN-HOUSE Pros

Fit / Customization

Modification

ConsCostRisk

STATISTICALLY SPEAKING, THIS COULD BE YOUR

PROJECT(62% OF IT PROJECTS FAIL)

HOW DO WE DEVELOP A SYSTEM?

SEVERAL FRAMEWORKS TO FOLLOW

Code and fix

Iterative and Incremental

Development

Spiral Model

Which one do I choose?

Waterfall Model

Agile Development

GENERAL STEPS IN THE SOFTWARE DEVELOPMENT LIFE CYCLE1. Planning Phase

2. Analysis Phase

3. Design Phase

4. Implementation Phase

5. Evaluation Phase

6. Maintenance

WATERFALL MODEL

WATERFALL MODEL Pros

Cheaper than making changes later in the process

Emphasis on documentation

Big design up front

Simple

ConsOnly effective for

non-trivial projects

InflexibleMight not be

aware of future requirements up front

SPIRAL MODEL

SPIRAL MODEL Pros

Iterative / FlexibleGood for large,

expensive and complicated projects

Promotes risk management

Don’t need to know all of the requirements

ConsExpensiveSlowOver budgetOver scope

ITERATIVE AND INCREMENTAL DEVELOPMENT

ITERATIVE AND INCREMENTAL DEVELOPMENT Pros

Get user feedback early

Understand requirements

Documentation

ConsExpensiveSlowOver budgetOver scope

AGILE DEVELOPMENT

ITERATIVE AND INCREMENTAL DEVELOPMENT Pros

FastUser Involvement Flexible

ConsBacktrackingScope CreepCost

CODE AND FIX

ITERATIVE AND INCREMENTAL DEVELOPMENT Pros

Not a lot of up-front work

Less Expensive (if you develop the right product)

ConsOnly good for

small projectsWrong productDoesn’t meet

business requirements

GENERAL STEPS IN THE SOFTWARE DEVELOPMENT LIFE CYCLE1. Planning Phase

2. Analysis Phase

3. Design Phase

4. Implementation Phase

5. Evaluation Phase

6. Maintenance

THE PLANNING STAGE

THE PLANNING PHASE 1. Define the Problem

2. Produce the Project Schedule***

3. Confirm Project Feasibility

4. Staff the Project

5. Launch the Project

*** We’ll do this in our project management lecture

DEFINE A PROBLEM STATEMENT Understand the Organization

What are the objectives of the organization? How does the organization work? How is it run? What is the organizational culture?

Both general culture and major sub-cultures When doing the requirements gathering you will

delve more into the details of particular sub-cultures.

CONSIDER THIS REQUEST: We need a knowledge management

system. When employees leave our organization, their knowledge leaves with them. Thus, it feels like our organization is reinventing the wheel every couple of years! We need a system that can capture and document employees knowledge, and then make it possible for future employees to access this documentation. Only managers should be able to delete knowledge. Our IT staff will enter the system to format and organize the data.

BASELINE

CASE STUDY 1: GOOGLE

GOOGLE KMS

CASE STUDY 2: PATAGONIA

PATAGONIA KMS

WHAT WOULD YOU DO? Based on the culture of these two

organizations, what differences do you foresee in their associated knowledge management systems in the future?

ANALYSIS PHASE

THE ANALYSIS PHASE Most important part of this phase:

Defining the System Requirements

System Requirements – what the system needs to be able to do in terms of functionality/capabilities!

DEFINING SYSTEM REQUIREMENTS

We can start to define the system requirements based on events that affect the system.

Events have triggers, sources, use cases, responses, and destinations.

SYSTEM REQUIREMENTS ANALYSIS

To decide what kinds of functionality the system needs, we can create an event table.

Event Trigger Source Use Case Response Destination

Customer wants to check item availability

Item inquiry

Customer

Look up item availability

Item availability details

Customer

Customer places an order

Order inquiry

Customer

Place order Order details Customer

Time to produce transaction summary reports

“End of business day”

None Produce the reports

Reports summary

Management

ANOTHER EXAMPLEEvent Trigger Source Use Case Response Destinatio

nAn academic department wants to schedule a course

Scheduling request

Academic Department

Schedule a course

Class Schedule

System

A student wants to enroll in a course

Enrollment Request

Student Enroll student

Schedule Student

Class lists are distributed to faculty

“Beginning of Semester”

System Produce class list

Class List Faculty

YOU TRY THIS EVENT TABLE – KNOWLEDGE MANAGEMENT

Employees can post knowledgeEmployees can search knowledge Managers can delete postsStaff can format posts

Event Trigger Source Use Case Response Destination

YOU TRY THIS EVENT TABLE – KNOWLEDGE MANAGEMENT

Event Trigger Source Use Case Response Destination

SYSTEM REQUIREMENTS ANALYSIS

We have just looked at events that can be processed by the system.

Now we need to know the procedures of each process we defined as an event.

For this purpose, we will use Data Flow Diagrams.

DATA FLOW DIAGRAMS A Data Flow Diagram (DFD) is a

graphical system model that shows all of the main requirements for an information system in one diagram.

This includes inputs and outputs, processes, and data storage.

Difference between ERD and DFD?

SOME NEW SYMBOLS (YES!!!)

External Agent

Data Store

1ProcessData Flow

LEVELS OF ABSTRACTION There are a few levels of abstraction to

note when dealing with DFDs.

The context diagram is the highest level of abstraction. It contains only one process – the system itself – and the external agents that interact with the system.

CONTEXT DIAGRAM

Faculty Member

Academic Departmen

t

StudentCourse

Registration System

Schedule Data

Class List

Enrollment Request

Schedule

YOU TRY: CONTEXT DIAGRAM Give your system a name.

Context Diagrams are usually created directly from

Event Tables (sources and triggers are shown).

The Context Diagram defines the system’s scope.

DFD FRAGMENTS We then use the Use Cases defined in

the Event Table to create DFD Fragments.

Academic Departmen

t

1 Schedule Course

Course DataSchedule Data

ENROLL STUDENT You will need the external agent, the

data flows, process, and data stores.

Student2 Enroll Student

Enrollment Request

Schedule

Enrollment Data

Course Data

PRODUCE CLASS LIST You will need the external agent, the

data flows, process, and data stores.

Faculty Member

3 Produce Class List

Class List

Enrollment Data

Course Data

Faculty Member

3 Produce Class List

Class List

Enrollment Data

Course Data

Student2 Enroll Student

Enrollment Request

Schedule

Enrollment Data

Course Data

Academic Departmen

t

1 Schedule Course

Course DataSchedule Data

YOU TRY – KNOWLEDGE MANAGEMENT

SOME VERY BAD THINGS Black Hole – data goes into a process

and nothing comes out!

Miracle – nothing goes into a process and data comes out!

2 Enroll Student

Enrollment Request

Course Data

Student

2 Enroll Student

Schedule

Enrollment Data

Student

DIAGRAM 0: ALL TOGETHER

Academic Departmen

t

1 Schedul

e Course

Course Data

Enrollment Data

3 Produce

Class List

2 Enroll

Student

Student

Faculty Member

Schedule Data

Enrollment Request

Schedule

Class List

DIAGRAM 0: A LITTLE LESS ABSTRACTION

Diagram 0 contains all DFD fragments. Don’t worry… you won’t be required to perform this feat! But I will show you what one looks like.

Just focus on creating event tables, context diagrams, and DFD fragments.

Rome wasn’t built in a day.

DECISION TREES

THE DECISION TREE The Decision Tree is another Systems

Analysis tool that summarizes decision logic.

DECISION TREES ARE BASED ON DECISION VARIABLES To decide delivery charge, we look at the

following variables:

Purchase Cost Is it greater or less than $250?

Number of Items Purchased Is it greater than or equal to four? Or less than or

equal to three?

Delivery Day Is it next day delivery? 2nd day delivery? Or 7th day

delivery?

Purchase > 250?

# items

Delivery day

No Yes

<=3

>=4

<=3

>=4

next

next

next nex

t2nd 7th 2nd

7th 2nd7th 2nd 7th

DECISION MADE ON DELIVERY COST (in $)25 10 7.50 10 7.50 6 35 15 10 9.50 7.50 6

YOU TRY A DECISION TREE BASED ON THESE VARIABLES By looking at the following variables, we can

decide whether or not to expedite delivery.

Customer Type Are they a new customer or not?

Back Order Is the item on back order more than 25 days or

not?

Return Instructions Are detailed instructions to be included or not?

ACTIVITY DIAGRAM

SYSTEM SEQUENCE DIAGRAM

ASSIGNMENT 4

TOMORROW’S CLASS More systems analysis and design We will look at Project Management

This will include the Planning Phase of the SDLC

Cost/Benefit Analysis

Feasibility Analysis

Management techniques, in general