Introduction to Systems Analysis and Design

Objectives Understand the fundamental SDLC and its

four phases Understand the evolution of systems

development methodologies Be familiar with the different roles on the

project team

What ?

System Development Life Cycle :Process of how an

Information System can support business needs, designing the system, building it, and delivering it to users

Why ? Facts :

A survey by the Standish Group in 1996 found that 42% of all corporate IS project were abandoned before completion

A study by the General Accounting in 1996 found that 53% of all US Government IS projects were abandoned. The rest are delivered to the user significantly late, cost far more than planned, and have fewer features than originally planned

Major Causes of Project Failure

A real estate group in the federal government cosponsored a data warehouse with the IT department. A formal proposal was written by IT in which costs were estimated at $800.000, the project duration was estimated to be eight months, and the responsibility for funding was defined as the business unit’s.

The IT department proceeded with the project before it even knew if the project had been accepted. The project actually lasted two years because requirements gathering took nine months instead of one and a half,the planned user base grew from 200 to 2.500 and the approval process to buy technology for the project took a year. Three weeks prior to technical delivery, the IT director canceled the project. This failed endeavor cost the organization and taxpayers $2,5 million.

Why did the system fail? Why would

a company spend money and time on a project and then

cancel it? What could have been done to prevent this

No SDLC

Advantages Time A clear purpose

Disadvantages Lack of proper

documentation Hard to handle

complex system

With SDLC

Advantages Developers know what

should and should’nt be built

Clear documentation Easier to maintain

program

Disadvantages Different between

what’s written in paper and what’s actually implemented

Limits developer’s creativity

Conclusion Without an SDLC Model to follow, developers

can have a free hand of developing software. However, development of these software doesn’t have a clear view and it will never be viable in any business model.

As long as the laid out plans of SDLC are followed, the usability and success of the software is ensured. Maintenance and development of the software is also possible since parts could be possibly be reused in different programs.

Key Person of SDLC Is the key person in

SDLC The goal is not to

create a wonderful system, but to create value for organization

Have to clearly understand how the system would fit the organization’s goals, current business process, and other information systems to provide values

SDLC Phases

Planning

Each phase is composed of a series of steps, which rely upon techniques

that produce deliverables

SDLC Phases (2)

PlanningWhy build the system?

AnalysisWho, what, when, where will the system be?

DesignHow will the system work?

ImplementationSystem delivery

Phase 1 : PLANNING Identifying business value Analyze feasibility Develop work plan Staff the project Prepare to control and direct project OUTPUT : Project Plan

Phase 2 : ANALYSIS Developing analysis strategy Gathering requirements Combining analyses, system concept, and

models OUTPUT : System Proposal

Phase 3 : DESIGN Developing design strategy Designing system architecture : hardware,

software, network infrastructure, and interface design

Developing database and file specifications Building program design OUTPUT : System Specification

Phase 4 : IMPLEMENTATION System construction : developing and testing

the system System installation Establish a support plan for the system

Process Product

Planning

Analysis

Design

Implementation

Project Plan

System Proposal

System Specification

New System and Maintenance

Plan

System Development Methodologies

What is a methodology ? A formalized approach to implementing the

SDLC. Paradigm :

Process-centeredData-centeredObject oriented

Methodology CategorizationWaterfall

Parallel Structured

Design

Phased

Prototyping

Throwaway Prototyping

RAD

Extreme Programming

Scrum

Dynamic Systems Development Method

Agile

Methodology : Waterfall

Pros Cons

Identifies systems requirements long

before programming begins

Design must be specified on paper

before programming begins

Long time between system proposal and

delivery of new system

Methodology : Parallel

Rapid Application Development (RAD)

Adjusting the SDLC phases to get some part of the system developed quickly

Most RAD-based methodology recommend that analysts use special techniques and computer tools

Methodology : Phased Dev.

Methodology : Prototyping

Methodology : Throwaway Prototyping

Agile Development Focus on streamlining the SDLC by

eliminating much of the modeling and documentation overhead and time spent on those task.

Methodology : XP

Methodology : Scrum

Methodology : Dynamic System Development Method

How to select it ?

PROJECT ROLES

Project Team Roles

References http://en.wikipedia.org/wiki/Systems_Develop

ment_Life_Cycle Dennis, A. 2005. System Analysis and Design

with UML version 2.0.