System Analysis and Design

Rabie A. Ramadan, PhD

http://rabieramadan.org

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About my self

Rabie A. Ramadan

My website and publications • http://www.rabieramadan.org

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Class Information

I am not here to punish you

Trust yourself and do your best

I want you to learn and compete with others working on the same field

I want you to be confident when you speak with others

Class Information

You can bring anything to drink but NO FOOD PLEASE

When you come in , DO NOT knock on the door

When you want to leave , do not tell me Just leave but you will be counted as absent• I do not take attendance every class but sometimes I

do

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Class Information

Attendance is a vey important

Assignments must be delivered on time

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Class Information

Textbooks

Systems Analysis and DesignSystems Analysis and Design , , 22ndnd EditionEdition

Alan Dennis and Barbara Haley WixomJohn Wiley & Sons, Inc.

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Class Information Website

http://www.rabieramadan.org/classes/2011/sysanalysis/

IntroductionIntroduction

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Grading

Assig 5%Attendance 5%Exam1 15%Exam2 15%project 20%Final 40%

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Key Ideas

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Many failed systems were abandoned because analysts tried to build wonderful systems without understanding the organization.

The primarily goal is to create value for the organization.

Key Ideas

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The systems analyst is a key person analyzing the business, identifying opportunities for improvement, and designing information systems to implement these ideas.

It is important to understand and develop through practice the skills needed to successfully design and implement new information systems.

THE SYSTEMS DEVELOPMENT LIFE CYCLE

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Major Attributes of the Life Cycle

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The project --• Moves systematically through phases where each

phase has a standard set of outputs

• Produces project deliverables

• Uses deliverables in implementation

• Results in actual information system

• Uses gradual refinement

Project Phases

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Planning (Why build the system? How should the team go about building it?)

Analysis (Who uses system, what will it do, where and when will the system be used?)

Design (How will the system work?)

Implementation (System delivery)

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A simple process for making lunch

Planning

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Identifying business value

Analyze feasibility

Develop work plan

Staff the project

Control and direct project

Analysis

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Analysis strategy

Gathering business requirements

Requirements definition use cases

Process modeling

Data modeling

Design

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Design selection

Architecture design

Interface design

Data storage design

Program design

Implementation

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Construction• Program building

• Program and system testing

Installation• Conversion strategy

• Training plan

• Support plan

Processes and Deliverables

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Process Product

Planning

Analysis

Design

Implementation

System RequestFeasibility Analysis

Workplan

System Proposal

System Specification

New System and Maintenance Plan

SYSTEM DEVELOPMENT METHODOLOGIES

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What Is a Methodology?

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A formalized approach to implementing the Systems Development Life Cycle (SDLC)• A series of steps and deliverables

Methodology Categories

Process-Centered

Data-CenteredObject-

Oriented

Waterfall Development Methodology

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Pros and Cons of the Waterfall Methodology

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Pros Cons

Identifies systems requirements long

before programming begins

Minimizes changes to requirements as

project progresses

Design must be specified on paper

before programming begins

Long time between system proposal and

delivery of new system

Parallel Development Methodology

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Pros and Cons of Parallel Development Methodology

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Pros Cons

Reduces Schedule Time

Less Chance ofRework

Still Uses PaperDocuments

Sub-projects May BeDifficult to Integrate

Rapid Application Development (RAD)

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Incorporate special techniques and tools:• CASE tools

• JAD sessions

• Fourth generation/visualization programming languages

• Code generators

CASE tools

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Computer-aided software engineering (CASE)• Scientific application of a set of tools

and methods to a software system which is meant to result in high-quality, defect-free, and maintainable software products.

Modeling business / real-world processes and data flow.

Development of data models in the form of entity-relationship diagrams

JAD sessions

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Joint Application Development (JAD)

• Developed by Drake and Josh of IBM

• Crawford of IBM Toronto in a workshop setting.

• JAD was designed to bring system developers and users of

varying backgrounds and opinions together in a productive

as well as creative environment.

Three RAD Categories

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Phased development• A series of versions developed sequentially

Prototyping• System prototyping

Throw-away prototyping• Design prototyping

Phased Development Methodology

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Insert Figure 1-4 here

Pros and Cons of Phased Development Methodology

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Pros Cons

Users Get a SystemTo Use Quickly

Users Can IdentifyAdditional NeedsFor Later Versions

Users Work with aSystem that isIntentionally Incomplete

How Prototyping Works

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Pros and Cons of Prototyping Methodology

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Pros Cons

Users Interact withPrototype Very Quickly

Users Can IdentifyNeeded ChangesAnd Refine RealRequirements

Tendency to doSuperficial Analysis

Initial Design Decisions May

Be Poor

Throwaway Prototyping

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Pros and Cons of Throwaway Prototyping Methodology

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Pros Cons

Risks are Minimized

Important Issues areUnderstood Before the

Real System is Built

May Take LongerThan Prototyping

Agile Development: Extreme Programming

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Pros and Cons of Agile Methodologies

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Pros Cons

Fast Delivery of Results

Works Well in ProjectsWith Undefined or

Changing Requirements

Requires Discipline

Works Best in Small Projects

Requires MuchUser Input

Criteria for Selecting the Appropriate Methodology

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Clear user requirements Familiarity with technology Complexity of system Reliability of system Time schedule Schedule visibility

TEAM ROLES AND SKILLS

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Information Systems Roles

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Business analyst Systems analyst Infrastructure analyst Change management analyst Project manager

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Summary

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The Systems Development Lifecycle consists of four stages: Planning, Analysis, Design, and Implementation

There are six major development methodologies: the waterfall method, the parallel development method, the phased development method, system prototyping, design prototyping, and agile development.

There are five major team roles: business analyst, systems analyst, infrastructure analyst, change management analyst and project manager.