An Introduction

1. System Development Life Cycle
info1409 De Montfort University
Abdul Hameed
Roll No. 1059
Semester 1st
B.S (HONS) I.T (Morning))
Submitted to: Sir Inam

2. info1409 De Montfort University
Objectives
 Have been introduced to the Systems
Development Life Cycle.
 Learned about the stages (or steps) involved
in system analysis.

3. info1409 De Montfort University
Structured Analysis
 Structured analysis is the traditional
way of moving from old outdated, or
inefficient systems to new and improved
ones.
This tradition uses a concept called the
Systems Development Life Cycle.

4. info1409 De Montfort University
Systems request
 Planning a new system usually begins
with a formal request called a ‘system
request’
 The request describes problems, or
desired changes in an information
system or business process

5. info1409 De Montfort University
Systems Planning phase
 The systems request usually initiates
the Systems Planning phase of the
System Development Life Cycle.
 It can come from a top manager, a
planning team, a department head, or
even the IT Department of an
Organisation.

6. info1409 De Montfort University
Systems Planning
Systems planning is the first stage in the
System Development Life Cycle
In this first stage a preliminary
investigation will take place to identify
the nature and scope of the problem (or
business opportunity)

7. info1409 De Montfort University
The entire Systems
Development Life Cycle.(SDLC)
Describes activities and functions that all
systems developers perform, and consists
of the following steps (or stages):
1. System Planning (including Feasibility)
2. System Analysis
3. System Design
4. Systems Implementation
5. Systems Operation, support and security

8. info1409 De Montfort University
SDLC Models
 The systems Development Life cycle can be
described or modelled in different ways.
 The most usual and well known model is
called the ‘Traditional Life Cycle or (Waterfall)
model’
The following is an illustration of what is meant by the
‘Waterfall model’

9. info1409 De Montfort University
INFO1409 Systems Analysis
SDLC L05.ppt
© Copyright De Montfort University 2000
All Rights Reserved
Traditional Life Cycle
Systems
Investigation
Systems
Analysis
Systems
Design
Systems
Implementation
Support &
Maintenance
Feasibility
Study
Project
Selection
“Waterfall” Approach
May have iterations but
these are very costly

10. info1409 De Montfort UniversityPage 21 Shelley et al

11. info1409 De Montfort University
Activity time
Instructions:
Work with the student sitting next to you.
If you do not have one, then try to get involved
with a student or students either behind you,
or in front of you.
Take ONE stage each of the SDLC
Discuss and record what you think the
activities in that stage would be.

12. info1409 De Montfort University
Stage 1 –Systems Planning
After the systems request the preliminary
investigation begins
 A key part of this investigation is a Feasibility
Study
 The Feasibility study reviews the anticipated
costs and benefits to the Organisation and
recommends a course of action.

13. info1409 De Montfort University
Stage 2 – Analysis
The results of the preliminary investigation and
feasibility study lead to the second stage of
the SDLC.
The purpose of the Systems Analysis phase is
to build a logical model of the new system
The first step is requirements modelling.

14. info1409 De Montfort University
Analysis continued..
Requirements modelling
 In requirements modelling, the analyst
investigates the business processes to
document what the new system must do.
 Requirements modelling continues the
investigation that began in systems planning.

15. info1409 De Montfort University
Stage 3 - Systems Design
.
At this stage you design the User Interface
1. Identify all necessary inputs, outputs
and processes.
2. Design internal and external controls
3. Show programmers how to transform
the logical design into program modules
and code. (application architecture)

16. info1409 De Montfort University
Design (continued)
The result of the Design stage is
documented in the
System Design Specification
This is presented to Managers and users
for review and approval.

17. info1409 De Montfort University
Stage 4 -System Implementation
…involves the following activities:
 Programs are written, tested and
documented.
 The system is installed.
 Final preparations are made to convert
data to the new system’s files, and to
train users).
 A system evaluation is conducted

18. info1409 De Montfort University
Stage 5 –Systems Operation,
Support and security
During this stage, the IT staff maintain,
enhance and protect the system.
 Maintenance corrects errors, and
adapts to changes in the environment
such as new tax rates.
 Enhancement gives new features and
benefits.
 Security controls safeguard the system

19. info1409 De Montfort University
Well Designed Systems
“A well designed system will be secure, reliable,
maintainable and scalable. A scalable
development can expand to meet new
business requirements and volumes.
Information systems development is
always a work in progress”
Page 22 chapter 1 Shelley et al Systems Analysis & Design 6th
Ed.

20. info1409 De Montfort University
Alternative SDLC model
This alternative model focuses on the interaction of planning,
analysis and design tasks which leads to implementation
followed by operation and support.