Lecture Requirement engineering Chapter 3 Software elicitation

What

is Requirement Elicitation?
Participants in elicitation
Risks of requirements elicitation
Requirements elicitation techniques


The

most common causes of poor
quality, cost overruns and late delivery of
software: Incorrect, incomplete, or
misunderstood requirement
Requirements elicitation is “the process
of discovering the requirements for a
system by communicating with
customers, system users and others who
have a stake in the system development”


Gather

requirement from various sources:
identify requirement providers: stakeholders
Analyse the gathered information, looking
for implications, inconsistencies or
unresolved issues
Confirm understanding of the requirements
with the users

Synthesize appropriate statements of the
requirements


 Requirement

elicitation involves many people.

 Customer/Client:

Person who pays for the software
development. Ultimately, has the final word on what
will be the product
 Software engineer: Expert who knows the
technology and process -> produce the requirements
specifications
 The potential users: of the current system or future
systems  indicate which functions to maintain or
improve


 Articulation

problems:

The user can’t express their needs
The users may not aware of their needs or not

understand how the technology may be able to
help them

The user may aware of a need but be afraid of
express it.
Users and developers misunderstand concepts or
relationships because they have different meanings
for common terms(ex:implementation)


 Communication

Barriers:

Users and developers come from different worlds

and have different professional vocabularies
The users have different concerns from those of
developer (high-level attributes vs low-level
technical issues)
Different personality types and different value
systems among people


 Knowledge

and cognitive limitations

The users and developers don’t have enough

domain or technical knowledge
The users and developers don’t remember exactly
what was said  may misinterpret that

information late
Try to simplify the propblem or ignore parts of
problem  distort the problem
State the problem in terms of favored solution


 Human

behavior issues:

Requirement elicitations is a social process



human behavior issues are involved
Conficts and ambiguities in the roles of
stakeholders  lead to gap in requirements
Fear the new system will necessitate the changes
in behavior of individuals and group  withhold
information


 Technical

issues

The problems are becoming increasingly complex
Requirements change over time
There are many sources of requirements..

 Asking

 Observing

and inferring
 Discussing and formulating
 Negotiating
 Studying and identifying problems
 Discovering through creative process


Interview
Brainstorming
JAD

Prototype


 The

most commonly used requirements
gathering technique.
 Three main objectives:
Record information to be used as input

to

requirements analysis and modeling
Discover information from interviewee accurately

and efficiently
Reassure interviewee that his/her understanding
of the topic has been explored, listened to, and
valued


Process

consists of three important

steps:
Planning and preparation

Conducting the interview
Postinterview follow-up.


Planning

and preparation

Set goals and objectives for the interview
Select interviewees
Create an interview schedule
Designing Interview Questions

Closed-Ended Questions
Opened-Ended Questions
Probing Questions

Conducting

the interview

Make the interviewee comfortable and

confident
Be polite and respectful!
Take careful notes
Don’ t afraid to ask


Postinterview

follow-up

Prepare an interview report that

describes the information from the
interview.
Send the interview report to the
interviewee with a request to read it
and inform the analyst of clarifications
or updates.


Problem

solving stages includes:

Problem Identification
Idea Generation
Idea Selection (decision making)
Implementation
Brainstorming

requires multiple people,
the Project Manager functions as a
facilitator of the session


Two

main activities:

The Storm: Generating as many ideas as

possible (quantity, not quality) – wild is
good!
Idea Selection : Filtering out of ideas
(combine, clarify, prioritize, improve…) to
keep the best one(s) – may require some
voting strategy


 Planning

the Session

Define the problem
Identify participants
Create groups out of the participants (just 3-4

members/group). Each group should consist of
people from diverse and relevant backgrounds
 Conducting

the Session
 After the Brainstorming Session
Give a reward or recognize the participant
follow-up and monitor the solution to closure.


An

information gathering technique that
allows the project team, users, and
management to work together to
identify requirements for the system
JAD is a structured process
10 to 20 users meet together under the
direction of facilitator skilled in JAD
techniques.


Preparation

Pre-session Planning
Pre-work

Conduction
Summary

the JAD session


Pre-session

Planning

Evaluate project

Identify contentious issues and scope of JAD
session
Select JAD participants
Create preliminary agenda
Determine deliverables for the working
session
Enable participants to prepare for the session


Pre-work

Planning

Gather information
Clear schedules for the working session
Refine session agenda
Finalize pre-session assignments
Prepare material for session (flip-charts,

presentations, marker...)


Set-up

stage

Session leader welcomes participants,

presents task to be discussed, establishes
rules and what is on/off topic…
Generate

common understanding
Achieve agreement on decisions
Create the deliverables
Identify open issues and questions