ICT Class Tenth Meeting

System Analysis - Analysis Stage and Design Stage

SYSTEM ANALYSIS 

A system analysis is needed to improve an existing system. The figure on the right shows the steps in taking a system analysis.

A. ANALYSIS STAGE

• This analysis stage can be done in some steps:
• collecting data from the current system
• establishing the inputs, outputs and the processing done in the system
• problems identification
• agreeing the objectives with the customer
• identifying and agreeing the customer’s requirements
•  interpreting the customer’s requirements
• producing a cost-benefit analysis
• producing a data flow diagram.
• The fact finding stage which is the first stage in analysis stage can be done in 4 different ways:
• Observation 
• Advantages: inexpensive and reliable
• Disadvantages: workers may feel uncomfortable being watched and they might not do what they usually do
• Questionnaires
• Advantages: quick and inexpensive
• Disadvantages: inflexible and the number of returned questionnaires is very low
• Interviewing
• Advantages: flexible and reliable
• Disadvantages: interviewee cannot remain anonymous, time consuming and expensive
• Looking at existing paperwork
• Advantages: much information needed is obtained
• Disadvantages: time consuming and expensive overall

B. DESIGN STAGE

• After analyzing is done, the next stage is to design the recommended system for improvements. Here are the tasks that needs to be done:
• designing data capture forms/input forms
• designing screen layouts
• designing output forms and reports
• producing systems flowcharts and/or pseudo code
• selecting and designing validation rules that need to be used
• selecting the most appropriate data verification methods
• designing and agreeing the file structures and tables
• selecting and designing the hardware requirements
• selecting and designing the software requirements
• producing algorithms or program flowcharts
• designing a testing strategy/plan.
• There are 2 important tasks in design stage: 
• Verification - a way to prevent any errors that may occur during data copying process
• Double entry
• Data is entered twice by different people
• The computer compares 2 entries
• The computer identifies any differences
• Validation - data is checked to see if it satisfies certain criteria when input into a computer