Lecture 5 - Managing Requriements

Question 1

What is PEGS?

Answer 1

A way to define requirements, the aim is to execute:
- a Project
- in a certain Environment
- to achieve a certain Goals
- by developing a System
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Where each has its own components such as:
Project Book: tasks and schedule
Environment Book: stakeholders, goals
Goals Book: compontents and constraints
System Book: functionality and interfaces

Question 2

What is the difference between projects and goals?

Answer 2

• Project Requirements concern how the SW development will be carried out where as, Goals Requirements capture the business goals of the system why we are building it

Question 3

What is the difference between the system and the environment?

Answer 3

The system is the objects within the environment whereas the environment is any outside factor that can affect the requirement

Question 4

What are the sources of requirements?

Answer 4

“Requirements document”
Meeting minutes
PowerPoint presentations
Emails
Regulatory documents
Code

Question 5

What are the attributes for a good requirement specification?

Answer 5

• Concise
• Complete
• Testable
• Feasible
• Modifiable
• Traceable
• Easy to change

Question 6

What are the three parts of the requirement analysis framework?

Answer 6

• Functional model: use cases & scenarios
• Static analysis object model: class & object diagrams
• Dynamic model: sequence diagrams

Question 7

What is the goal of the requirement analysis framework?

Answer 7

Goal is to investigate the problem domain as far as possible before moving to the solution domain (i.e., design & implementation)

Question 8

What is a UML class diagram?

Answer 8

• A class diagram describes the types of objects in the system and the various kind of static relationships that exist among them.
• Class diagram also show the properties and operations of a class and the constraints that apply to the way objects are connected.
  REFER TO SLIDES FOR EXAMPLES

Question 9

What is multiplicity - in reference to UML class diagram?

Answer 9

The multiplicity of a property is an indication of how many objects may fill the property

Question 10

What are the 3 conditions of multiplicity?

Answer 10

1 can only have exactly 1
0..1 means between 0 to 1 (can also have 1 .. 5 or 0 .. *)
* no upper limit on how many there are

Question 11

What is Class Responsible Collaboration (CRC)?

Answer 11

Technique uses to analysis and organise classes within a system
NOTE: typically defines the role of the class and its collaborator (the other classes it links to if required)
REFER TO SLIDES FOR EXAMPLES

Question 12

What is the difference between Analysis and Validation?

Answer 12

• Analysis works with raw requirements as elicited from the system stakeholders
• Validation works with a final draft of the requirements document i.e. with negotiated and agreed requirements

Question 13

What are the validation outputs?

Answer 13

• Problem list
  – List of discovered problems in the requirements document
• Agreed actions
  – List of agreed actions in response to requirements problems. Some problems may have several corrective actions; some problems may have no associated actions
• Management tools for this
  – Requirements document with version tracking
  – Issue tracking support

Question 14

What are Requirement Reviews?

Answer 14

A group of people read and analyse the requirements, look for problems, meet and discuss the problems and agree on actions to address these problems

Question 15

What are the criteria of the review checklist?

Answer 15

• Understandability
  – Can readers of the document understand what the requirements mean?
• Redundancy
  – Is information unnecessarily repeated in the requirements document?
• Consistency
  – Do the descriptions of different requirements include contradictions? Are there contradictions between individual requirements and overall system requirements?
• Organisation
  – Is the document structured in a sensible way? Are the descriptions of requirements organised so that related requirements are grouped?
• Conformance to standards
  – Does the requirements document and individual requirements conform to defined standards? Are departures from the standards, justified?
• Traceability
  – Are requirements unambiguously identified, include links to related requirements and to the reasons why these requirements have been included?

Question 16

What are the checklist questions that can be asked?

Answer 16

• Is each requirement uniquely identified?
• Are specialised terms defined in the glossary
• Do individual requirements use the terms consistently
• Are related requirements grouped together? If not, do they refer to each other?

Question 17

What are the 10 test for requirements?

Answer 17

1. Does each requirement have a fit criterion that can be used to test whether a solution meets the requirement?
2. Is every requirement in the specification relevant to this system?
3. Does the specification contain a definition of the meaning of essential terms within the specification?
4. Is every reference to a defined term consistent with its definition?
5. Is the context of the requirements study wide enough to cover everything we
   need to understand?
6. Does the requirement contain a rationale?
7. Have we asked the stakeholders about conscious, unconscious and undreamed of requirements?
8. Does the specification contain solutions posturing as requirements?
9. Is the stakeholder value defined for each requirement?
10. Is each requirement uniquely identifiable?