10-Lecture X

(1)

COMSATS Institute of Information Technology, Attock

1 _{Farhan Aadil}

Farhan Aadil

Assistant Professor

COMSATS Institute of Information Technology

Lecture 10

Requirement Elicitation

(2)

2 _{Farhan Aadil}

(3)

3 _{Farhan Aadil}

3

Requirements Elicitation - 1

• Elicit means to gather, acquire, extract, and obtain, etc.

• Requirements elicitation means gathering requirements or

(4)

4 _{Farhan Aadil}

4

Requirements Elicitation - 2

(5)

5 _{Farhan Aadil}

5

Basics of Knowledge Acquisition

• Reading

• Listening

• Asking

• Observing

(6)

6 _{Farhan Aadil}

6

Requirements Elicitation Techniques

• Individual

• Group

• Modeling

(7)

7 _{Farhan Aadil}

7

Problems in Requirements Elicitation

• Problems of scope

(8)

8 _{Farhan Aadil}

8

Problems of Scope

• The boundary of the system is ill-defined

(9)

9 _{Farhan Aadil}

9

Problems of Understanding - 1

• Users have incomplete understanding of their needs

• Users have poor understanding of computer capabilities and

limitations

(10)

10 _{Farhan Aadil}

10

Problems of Understanding - 2

• User and analyst speak different languages

• Ease of omitting “obvious” information

• Conflicting views of different users

(11)

11 _{Farhan Aadil}

11

Problems of Volatility

(12)

12 _{Farhan Aadil}

12

Contexts in Requirements Elicitation Process

• Organization

• Environment

• Project

• Constraints imposed by people

It

is important to consider the context in which

requirements are being elicited. Requirements

elicitation process may be followed in the

(13)

13 _{Farhan Aadil}

13

Contexts in Requirements Elicitation Process - 1

• Organization

– Submitters of input

– Users of output

(14)

14 _{Farhan Aadil}

14

• Environment

– Hardware and software

– Maturity of the target system domain

(15)

15 _{Farhan Aadil}

15

• Project

– The attributes of the different stakeholder communities, such as the

end users, sponsors, developers, and requirements analysts.

Examples of such attributes are:

(16)

16 _{Farhan Aadil}

16

• The constraints imposed by the people

(17)

17 _{Farhan Aadil}

17

Requirements Elicitation Guidelines - 1

• Assess the business and technical feasibility for the

proposed system

• Identify the people who will help specify requirements

and understand their organizational bias

• Define the technical environment

(18)

18 _{Farhan Aadil}

18

• Define one or more requirements elicitation

methods (interviews, focus groups, team meetings)

(19)

19 _{Farhan Aadil}

19

• Identify ambiguous requirements as candidates for

prototyping

(20)

20 _{Farhan Aadil}

20

Ethnomethodology

• Looks for behaviors that may be different in

a specific culture but which have the same

underlying purpose or meaning

• Conversational/Informal analysis

• Measurement of body system functions

• Non-verbal behavior studies

(21)

21 _{Farhan Aadil}

21

Requirements and Psychology

• Errors in statements can happen in two

places

– Perception of facts – reality

– Linguistic representation of one of these

perceptions – personal reality

(22)

22 _{Farhan Aadil}

22

Use Case Modeling

• Define actors and black-box use cases

• The functional requirements of the system

are defined in terms of use cases and

actors

(23)

23 _{Farhan Aadil}

23

Summary - 1

• Introduced the concept of elicitation and

requirements elicitation process

• Basics of knowledge acquisition (reading,

listening, asking, & observing)

• Knowledge acquisition techniques

(individual, group, modeling, cognitive)

• Elicitation problems (scope,

(24)

24 _{Farhan Aadil}

24

Summary - 2

• Context (organization, environment,

(25)

25 _{Farhan Aadil}

25

References

• ‘Requirements Engineering: Processes and

Techniques’ by G. Kotonya and I. Sommerville,

John Wiley & Sons, 1998

• Software Requirements: Objects, Functions,

and States by A. Davis, PH, 1993

• Software Engineering 6

th

Edition, by I.

Sommerville, 2000

• Software Engineering 5

th

Edition, by R.