Chapter 6System Analysis-Gathering

Requirements

System analysis is the process of gathering info about existing system, which may be computerized or not, while identifying system’s strengths and problems.

Commonly used info gathering techniques are:• Interviews• Review of document• Observation• Questionnaires• Joint Application Design• Prototyping

Interviews• Reveals info about the interviewee opinions

about existing system.• 4 basic steps in an interview are :-

Read the background materials to establish the interview objectives

Decide who to interview Prepare the interview Decide on question type and structure

• It is a formal face to face meeting between system development team and user

• There are two types of interview: Structured

The interviewer will only ask questions that have been planned and write in advance

Unstructured The interviewer will ask questions that have been

prepared earlier and also other subjects if they seem appropriate

• Advantages : Get to meet the person personally and get more

info if asked correctly Reveals what actually being done Indications of resistance to the proposed system

• Disadvantages: Time consuming to undertake More costly

Review of documents• Written doc includes manuals, procedures,

forms reports etc• Copies of documentation should be able for

review• Reviewing such documentation can reveal

about the organization, operation and its existing system

• It is important to: Identify a complete list of doc

Go through them Analyze Check for duplication of data to ensure it is not

appear under two names• By reviewing doc, more effective interviews

can be conduct with managers and users. Observation

• Allows to gain info that cannot get by other techniques

• First hand info can be obtained• Direct observation is where system analyst

watches the users as they performing their job function

• It enables us to see the reality situation rather than listening to others

• Used as supplementary interview info or acts as a signal any extra care to be taken into account

Questionnaires• Are used when there are large number of

users• The questions should be reasonably

straightforward and relatively few to increase the likelihood of response

• Cheaper and quicker way to interview but difficult to set a clear questions and ensure adequate response rate

• Advantages : Obtain info from large number of people with less time and money

• Disadvantages : Info maybe less detailed Info could be bias if only a few respond to the survey

Joint Application Design• Info gathering technique that allows a system dev team, users and

mgt to work together in a focused workshop to identify requirements for the system

• Effective in building user commitment through their participation in analysis of requirements and specifications of systems design

• Advantages : It takes shorter time to complete a project Improves the quality of final system by focusing on up-front SDLC,thus

reducing errors

Prototyping• is a model of a proposed system• Acts as a communications device between

users and system dev team and aid in the learning process

• Has five main stages : Agree approximately what is needed Build something quickly that look like what is

wanted Test it and see if it does what the user wants

Use it in a representative environment Adapt and develop the prototype based on the

info gained• Advantages:

Improve info gathering technique process Improve relationship between system dev team

and user Better identification of systems problems

• Disadvantages : Potential cause of conflict between dept that

want different things from the system

Misunderstanding by end user that actual system can be design and dev at same speed