1. Modern Systems Analysis and Design Third Edition
Chapter 6
Determining System Requirements
7.1

2. Performing Requirements Determination
System Analysis phase has three sub phases
Requirements determination
Requirements structuring
Generating alternative design and selecting best one
Gather information on what system should do from many sources
Users
Reports
Forms
Procedures

3. Performing Requirements Determination
Characteristics for gathering requirements
Impertinence
Question everything
Impartiality
Find the best organizational solution
Relaxation of constraints
assuming anything is possible
Attention to detail
Reframing
View the organization in new ways
7.3

4. Deliverables and Outcomes
Types of deliverables:
Information collected from users
interview transcripts, questionnaire responses, notes of observation
Existing written information
sample business forms and reports, procedure manuals, training manuals
Computer-based information
CASE repository contents and reports of existing system
Understanding of organizational components
Business objective
Information people needs
Data handled and when, how and who moves data
Rules of data processing
7.4

5. Traditional Methods for Determining Requirements
Individually interview people who knows current system
Survey people via questionnaires
Interview group of people with different needs
Observe workers at selected times to see how data is handled
Study business documents
Interviewing and Listening
Guidelines for Effective Interviewing
Prepare interviewee: set up appointment time and duration convenient for interviewee
Prepare checklist, agenda and questions, to know the sequence and duration of questions to ask
Listen carefully and take notes
Review notes within 2 days of interview
Be neutral and seek diverse views
7.5

6. Traditional Methods for Determining Requirements
Questionnaires Vs Interviews
Interviews are very expensive and time-consuming
Questionnaires are not expensive and can gather information from many people simultaneously in a relatively short time
Interviews can have limited number of questions and limited number of people contacted
Questionnaires give less depth of understanding
Interviews provide the opportunity to judge the truthfulness of responses by the words or voice tone or the body language of the respondent
Questionnaires do not provide the opportunity to judge the accuracy of responses
7.6

7. Traditional Methods for Determining Requirements
Choosing Questionnaire respondents – if more people to survey decide which set of people to send questionnaire to or which questionnaire to send to which group of people
Designing Questionnaires
Questionnaires are most useful when used for specific purpose and not for general information gathering
Questionnaires typically include closed-ended questions
Questionnaires must be extremely clear in meaning and logical in sequence
How often(?) do you backup your computer files (C: or hard disk)?
a) frequently b) sometimes c) hardly at all d) never
7.7

8. Traditional Methods for Determining Requirements
Interviewing Groups – interview several key people at once by several analysts, one asks questions other takes notes
Advantages
More effective use of time
Enables people to hear opinions of others and to agree or disagree
Disadvantages
Difficulty in scheduling convenient time as many people are involved
7.8

9. Modern Methods for Determining Requirements
A. Joint Application Design (JAD)
Similar to group interview as it brings together key users, managers and systems analysts
Purpose: collect system requirements simultaneously from key people
Particular structure of roles and agenda is followed and analysts control the sequence of questions answered by users
may last from four hours to an entire week and may consist of many weeks
B. Prototyping
Goal: to develop concrete specifications for ultimate system
4.9

10. B. Prototyping
Quickly converts requirements to working version of system
Once the user sees requirements converted to system, will ask for modifications or will generate additional requests
Most useful when:
User requests are not clear
Few users are involved in the system
Designs are complex and require concrete form
History of communication problems between analysts and users
Tools are readily available to build prototype
Drawbacks
Tendency to avoid formal documentation
Difficult to adapt to more general user audience
Sharing data with other systems is often not considered
Systems Development Life Cycle (SDLC) checks are often bypassed
7.10