THE SYSTEMS LIFE CYCLE

ANALYSE

DESIGN

IMPLEMENT

MAINTENANCE

IDENTIFY/INVESTIGATE

2.Analyse The Problem3. Design A Solution4.Implement Your solution5. Maintain the solution

1.Identify/Investigate problem

Identify/Investigate problem

1. How does the current system operate

2. What does the current system not do

3. What should the new system be able to do

4. What are some alternative solutions

5. A recommended course of action

If the Identification recommends that the project can go ahead:

1.Make out a list of Objectives/Criteria

2.Begin the Analysis

List of Objectives/Criteria

These should be kept simple and should be referred to

throughout the coursework to ensure you are achieving what

you set out to do eg.

游The output must be easy to read and understand

游Test the solution using suitable test data

游Produce a template that can be re used

Analyse The Problem

Examine what problems exist within the current system by asking

questionsWhat is being done now ?

Why is it being done ?

Who is doing it ?

How is it being done ?

Questionnaires

Interviews

Observation

Analyse The ProblemFact-finding methods

used to gather information

Examining Docs

The investigation is used to produce a

detailed description of the current system

including the use of

Data Flow Diagrams

and

Systems Flowcharts See page 216 to 219 of text

What are the drawbacks of this solution ?

How long will development take ?

Design A Solution

What hardware does the solution require ?

What benefits does this new solution offer ?

How much will this solution cost ?

Identify the alternative possible solutions

Design A Solution

Input

Output

Data Storage

User Interface

Back up procedures

Security Procedures

Test Plan

Having identified the best solution produce a detailed design

specification

Create data files

Set up validation checks

Enter enough data to test the system

Implement A solutionSet up the system so that it

matches the design specification

Create input/output screens

Set up the user interface

Set up system security

Extreme data - data that lies at the boundaries of acceptable input

Normal data - expected during day to day use

Implement A solutionWhen testing the system use

the plan prepared during the design stage

Erroneous data - data that lies outwith the boundaries

Phased Implementation -Introduce the new system in smaller parts

Direct Implementation - Instantaneous change from old to new system.Quick but very disruptive if errors found

Implement A solutionIt is now possible to install the new

system

Parallel Implementation -Run both systems simultaneously over a period.Longer to operate. No disruption from errors

Implement A solutionFinally, documentation must

be produced for the system

Technical Documentation

User Documentation

Screen Layouts and UI Designs

Implement A solutionTechnical

Documentation

System Design Specification

Flowcharts

Description of the system

The Test Plan

Additional Support [Help Lines]

Implement A solutionUser

Documentation

Minimum System requirements

Loading Instructions Meaning of Error Messages

Operating instructions

MaintenanceSome time after installation, a

new system may need to be changed

• to satisfy the needs of the user

• to correct problems

• to improve the system

The solution to each problem must be evaluated to check

it’s success

Evaluation

Is the PROBLEM solved ?

Have the Objectives/criteria been met ?

Did the test data work ?

How can the system be improved ?

Chapter 10 pgs 215 - 244

gives a detailed breakdown of the requirements to be met for

your coursework projects