This document discusses various methods for determining system requirements in the systems development life cycle (SDLC). It describes traditional methods like administering questionnaires, interviewing stakeholders, observing users, and analyzing documentation. It also discusses structuring requirements by viewing the system's process flow and data structure. Modern methods mentioned include prototyping, joint application design sessions, using group support systems, business process reengineering, and CASE tools.

1. Determining System
Requirements

2. SDLC
Project Identification
& Selection
Project Initiation
& Planning
Analysis
**
Logical Design
Physical Design
Implementation
Maintenance

3. Requirements Determination
 System requirements
 Functional requirements

Current and future functions

Current and future data

Current and future employee jobs

4. Requirements Structuring
 Two essential views of the current and
replacement information systems. Both are
describing the same system, but in a different
way.
 Process view: The sequence of data movement &
handling operations within the system

Data flow diagrams
 Data: The inherent structure of data independent of
how or when it is processed

Entity-relation diagrams

5. Remember to...

6. Who will you get info from?
 User Stakeholders
 Users
 Managers
 Client Stakeholders
 Technical Stakeholders

7. What Information Do You
Need?
 1.
 2.
 3.

8. Traditional Methods for
Determining System
Requirements
 Administering questionnaires
 Interviewing and listening
 Interviewing groups
 Directly observing users
 Analyzing procedures & other
documents

9. Administering Questionnaires
Advantages & Disadvantages
 Strengths
 1.
 2.
 3.
 Weaknesses
 1.
 2.
 3.

10. Give Me Ambiguity or Give Me
Something Else!
 How often do you back up your
computer files?
 A. Frequently
 B. Sometimes
 C. Hardly at all
 D. Never

11. This is better…
 How often do you back up the computer
files stored on the hard disk on the PC
you use for over 50% of your work
time?
 A. Frequently (at least once per week)
 B. Sometimes (from 1 to 3 times per
month)
 C. Hardly at all (once per month or less)
 D. Never

12. Interviewing & Listening
 Before
 During the interview
 Afterwards

13. During the Interview
 Beginning
 Introduction, open-ended questions, interest &
attention
 Middle
 Open & close-ended questions, f-u questions,
active listening, provide feedback, limit note-taking
 End
 Summarize, request feedback and/or f-u, ask for
corrections

14. Interviews
Advantages & Disadvantages
 Strengths
 Extracts both
qualitative and
quantitative data
 Detailed and
summary data
 Good way to find
needs and
assumptions
 Weaknesses
 Requires skills
 May be biased; May
collect lots of useless
data
 Expensive, time
consuming
 Requires other
methods to verify
results

17. How do you choose
interview questions?
 Open-ended questions
 1.
 2.
 3.
 Closed-ended questions
 1.
 2.
 3.

18. Find out about someone’s
job
 Write 3 open-ended
questions
 Ask 3 open-ended
questions (You may
substitute questions
during interview.)
 Write down answers
 Write 3 closed-ended
questions
 Ask 3 closed-ended
questions (You may
substitute questions
during interview.)
 Write down answers

19. Interviewing Groups
Adv & Disadv
 Strengths
 Not biased by one
user’s opinion
 Can get many user’s
opinion
 Weaknesses
 With many people
present, decision-
making takes time
 Interruptions during
process

20. You May Need to Analyze
Work Procedures
 Work procedures describe a particular
job or task
 May show duplication of effort
 May find missing steps
 May contradict info collected from
interviews, questionnaires, and
observations
 Formal systems vs informal systems

21. Directly Observing
Users
 Strengths
 Doesn’t rely on a
user’s memory
 More objective and
accurate than
interviews
 Weaknesses
 Hawthorne effect
 Time consuming

22. Temporary Job Assignment
 Strengths
 Good for learning
context, terminology,
procedures
 Provides insight for
other questions
 Get operation “feel”;
adds to analysts
credibility with users
 Weaknesses
 Time Consuming
 May bias future work
design towards way
things are currently
done

23. Reviewing internal documents
 Strengths
 Good way to learn
history and politics
 Explains current
context
 May help understand
why and way of
current procedures &
applications
 Weaknesses
 May bias future work
design
 Not useful for
obtaining current
attitudes or motives

24. Modern Methods for Determining
System Requirements
 Prototyping
 Joint Application Design (JAD) - Intensive
meetings between users, managers, sponsor,
& systems analysts to discuss & review
system requirements
 Group Support Systems (GSS) to share ideas
& voice opinions
 BPR – Business process reengineering
 CASE tools to analyze existing systems