REQUIREMENTS
DETERMINATION
WHAT IS A
REQUIREMENT?
A statement of what the system must do
A statement of characteristics the system must
have
Focus is on business user needs during analysis
phase
Requirements will change over time as project
moves from analysis to design to implementation
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REQUIREMENT TYPES
Functional Requirements
A process the system has to perform
Information the system must contain
Nonfunctional Requirements
Behavioral properties the system must have
Operational
Performance
Security
Cultural and political
MYRIAM.LEWKOWICZ@UTT.FR 3
DOCUMENTING
REQUIREMENTS
Requirements definition report
Text document listing requirements in outline form
Priorities may be included
Key purpose is to define the project scope: what
is and is not to be included.
MYRIAM.LEWKOWICZ@UTT.FR 4
DETEMINING
REQUIREMENTS
TECHNIQUES
Interviews
Questionnaires
Documents analysis
Observation
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INTERVIEWS
Most commonly used technique
Basic steps:
Selecting Interviewees
Designing Interview Questions
Preparing for the Interview
Conducting the Interview
Post-Interview Follow-up
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SELECTING
INTERVIEWEES
Based on information needs
Best to get different perspectives
Managers
Users
Ideally, all key stakeholders
Keep organizational politics in mind
MYRIAM.LEWKOWICZ@UTT.FR 7
THREE TYPES OF
QUESTIONS
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DESIGNING INTERVIEW
QUESTIONS
Unstructured interview useful early in
information gathering
Goal is broad, roughly defined information
Structured interview useful later in process
Goal is very specific information
MYRIAM.LEWKOWICZ@UTT.FR 9
TOP-DOWN AND BOTTOM-
UP QUESTIONING
STRATEGIES
MYRIAM.LEWKOWICZ@UTT.FR 10
PREPARING FOR THE
INTERVIEW
Prepare general interview plan
List of question
Anticipated answers and follow-ups
Confirm areas of knowledge
Set priorities in case of time shortage
Prepare the interviewee
Schedule
Inform of reason for interview
Inform of areas of discussion
MYRIAM.LEWKOWICZ@UTT.FR 11
CONDUCTING THE
INTERVIEW
Appear professional and unbiased
Record all information
Check on organizational policy regarding tape
recording
Be sure you understand all issues and terms
Separate facts from opinions
Give interviewee time to ask questions
Be sure to thank the interviewee
End on time
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POST-INTERVIEW
FOLLOW-UP
Prepare interview notes
Prepare interview report
Have interviewee review and confirm interview
report
Look for gaps and new questions
MYRIAM.LEWKOWICZ@UTT.FR 13
QUESTIONNAIRES
A set of written questions, often sent to a large
number of people
May be paper-based or electronic
Select participants using samples of the population
Design the questions for clarity and ease of analysis
Administer the questionnaire and take steps to get a
good response rate
Questionnaire follow-up report
MYRIAM.LEWKOWICZ@UTT.FR 14
GOOD QUESTIONNAIRE
DESIGN
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DOCUMENT ANALYSIS
Study of existing material describing the current
system
Forms, reports, policy manuals, organization
charts describe the formal system
Look for the informal system in user additions to
forms/report and unused form/report elements
User changes to existing forms/reports or non-use
of existing forms/reports suggest the system
needs modification
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OBSERVATION
Watch processes being performed
Users/managers often don’t accurately recall
everything they do
Checks validity of information gathered other ways
Be aware that behaviors change when people are
watched
Be unobtrusive
Identify peak and lull periods
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SELECTING THE
APPROPRIATE
REQUIREMENTS-
GATHERING TECHNIQUES
Type of information
Depth of information
Breadth of information
Integration of information
User involvement
Cost
Combining techniques
MYRIAM.LEWKOWICZ@UTT.FR 18
COMPARISON OF
REQUIREMENTS-
GATHERING TECHNIQUES
MYRIAM.LEWKOWICZ@UTT.FR 19
