REQUIREMENTS ENGINEERING II

Question 1

Describe requirements elicitation

Answer 1

AKA requirements discovery
 Involves technical staff working with customers to
find out about
-the application domain,
-the services that the system should provide and
-the system’s operational constraints.
 May involve end-users, managers, engineers
involved in maintenance, domain experts, trade
unions, etc. These are called stakeholders.

Question 2

What are the possible problems of requirements analysis?

Answer 2

 Stakeholders don’t know what they really want.
 Stakeholders express requirements in their own terms.
 Different stakeholders may have conflicting
requirements.
 Organizational and political factors may
influence the system requirements.
 The requirements change during the analysis
process. New stakeholders may emerge and the business environment may change.

Question 3

What are the stages of requirements and analysis

Answer 3

 Requirements discovery
Interacting with stakeholders to discover their requirements. Domain requirements are also discovered at this stage
Methods that can be used here include???
 Requirements classification and organization
-Groups related requirements and organizes them into
coherent clusters
 Prioritization and negotiation
-Prioritizing requirements and resolving requirements conflicts
 Requirements specification
-Requirements are documented and input into the next round of the spiral

Question 4

What is requirements validation and why is it important?

Answer 4

 Concerned with demonstrating that the requirements define the system that the customer really wants
 Requirements error costs are high so validation is very important
-Fixing a requirements error after delivery may cost up to 100 times the cost of fixing an implementation error

Question 5

Give examples requirement validation techniques

Answer 5

 Requirements reviews: Systematic manual analysis of the requirements
 Prototyping: Using an executable model of the system to check requirements
 Test-case generation: Developing tests for requirements to check testability

Question 6

Describe requirements management and what it entails

Answer 6

 Requirements management is the process of managing changing requirements during the requirements engineering process and system development
 New requirements emerge as a system is being developed and after it has gone into use
 Tracking of individual requirements and maintaining links between dependent requirements helps in assessing the impact of requirements changes
 Establish a formal process for making change proposals and linking these to system requirements

Question 7

What are some of the requirement management challenges

Answer 7

 The business and technical environment of the system always changes after installation
 The people who pay for a system and the users of that system are rarely the same people
 Large systems usually have a diverse user community, with many users having different requirements and priorities that may be conflicting or contradictory

Question 8

Illustrate requirements evolution

Answer 8

*See notes

Question 9

Feasibility study is also mentioned as a part of the software specification process. Describe it

Answer 9

Feasibility study
 Is it technically and financially feasible to build the system?
 ROI, product vision, what market share are we after? Urgency of development?