copyright © jerzy r. nawrocki requirements review [email protected] requirements...
TRANSCRIPT
Copyright © Jerzy R. Nawrocki
Requirements ReviewRequirements Review
[email protected]/jnawrocki/require
Requirements Engineering & Project Management
Lecture 5
J.Nawrocki, Requirements Review
Introduction
Cost of Error Correction
0
20
40
60
80
100
120
Req. Design Code Dev.Tst Sys.Tst Field Op.
Development Phase
Re
lati
ve
Co
st
Roger S. Pressman
13-6
times
10 times
15-40 times
30-70 times
40-1000 times
J.Nawrocki, Requirements Review
Quality-supporting activities
Refacto
ring
Testin
g
Co
nfig
uratio
n m
anag
.
Review
s
Software Quality
J.Nawrocki, Requirements Review
Quality-supporting activities
Refacto
ring
Testin
g
Co
nfig
uratio
n m
anag
.
Review
s
Software Quality
J.Nawrocki, Requirements Review
Agenda
•Requirements Analysis & Negotiation•Requirements Validation
• Introduction• XPrince Team• Project Lifecycle• The Analyst Role• The Architect Role• The Project
Manager Role• Scaling up• Conclusions
J.Nawrocki, Requirements Review
Requirements Analysis and Negotiation
The requirements document
Requirements elicitation
Reqs analysis & negotiation
Describing requirements
System modelling
Requirements validation
Requirements management
RE for critical systems
Basic Interm Adv
8
6
54
3
4
4
2
36
-
6
21
3
3
3
3
21
-
1
1-
-
1
2
4
9
J.Nawrocki, Requirements Review
Basic guidelines
Analysis and negotiation
Define system boundaries
SystemSystem
Person 1
Person 2
Institution
Device
• Process requirements• System requirements• Software requirements
J.Nawrocki, Requirements Review
Basic guidelines
Analysis and negotiation
Define system boundariesUse checklists for requirements analysis
J.Nawrocki, Requirements Review
A Checklist Example
• Does a requirement imply the need for some decision-making based on incomplete or unreliable information?
• Will the implementation of a requirement need information which is outside the defined database for the system?
• Is a requirement concerned with the core functionality of the system?
• Is a requirement concerned with the functionality or performance of equipment which is external to the system?
Analysing system’s boundaries
J.Nawrocki, Requirements Review
Another Checklist Example
a) Correct;b) Unambiguous;c) Complete;d) Consistent;e) Ranked for importance and/or stability;f) Verifiable;g) Modifiable;h) Traceable.
IEEE Std 830-1998
J.Nawrocki, Requirements Review
A Checklist for Use Cases
Is there a shared clear vision?Are there visible boundaries?Is there clear cast of characters describing end-users?Are all user-level use-cases user-valued transactions?Does each use case have a complete single goal?Is its naming clear and depicting the goal?Are the alternatives an exhaustive set?Are use cases describing just behaviour?Are adornments properly used?Are the conditions detectable?
J.Nawrocki, Requirements Review
Basic guidelines
Analysis and negotiation
Define system boundariesUse checklists for requirements analysis
Provide software to support negotiationsProvide software to support negotiations
Plan for conflicts and conflict resolution
Prioritise requirements
J.Nawrocki, Requirements Review
Intermediate guidelines
Analysis and negotiation
Classify requirements using a multidimensional approach
System, User interface, Database, Communications, Security
J.Nawrocki, Requirements Review
Intermediate guidelines
Analysis and negotiation
Classify requirements using a multidimensional approach
Use interaction matrices to find conflicts and overlaps
System, User interface, Database, Communications, Security
J.Nawrocki, Requirements Review
Advanced guidelines
Analysis and negotiation
Assess requirements risks
J.Nawrocki, Requirements Review
Agenda
•Requirements Analysis & Negotiation•Requirements Validation
• Introduction• XPrince Team• Project Lifecycle• The Analyst Role• The Architect Role• The Project
Manager Role• Scaling up• Conclusions
J.Nawrocki, Requirements Review
Requirements Validation
The requirements document
Requirements elicitation
Reqs analysis & negotiation
Describing requirements
System modelling
Requirements validation
Requirements management
RE for critical systems
Basic Interm Adv
8
6
54
3
4
4
2
36
-
6
21
3
3
3
3
21
-
1
1-
-
1
2
4
9
J.Nawrocki, Requirements Review
Basic guidelines
Requirements validation
Check that the requirements document meets your standardOrganise formal requirements inspections
J.Nawrocki, Requirements Review
Artefact
Reviews and Inspection
Review = Analysis of an artefact (e.g. code, document) done by 1 or more people.
Goals of review:Quality assuranceKnowledge dissemination
Review
J.Nawrocki, Requirements Review
FTR Procedure
Casting
Producer (author)Project ManagerFacilitatorReviewer(s)Recorder
FTR = Formal Technical Review
J.Nawrocki, Requirements Review
FTR Meeting
Decision
Acceptance. No modifications are necessary.
Conditional acceptance. There are some defects but additional inspection is not necessary (the Project Manager will check the final version).
Rejection. There are serious defects and an additional inspection is necessary.
J.Nawrocki, Requirements Review
Basic guidelines
Requirements validation
Check that the requirements document meets your standardOrganise formal requirements inspections
Use multidisciplinary teams to review requirements
Define validation checklists
J.Nawrocki, Requirements Review
Intermediate guidelines
Requirements validation
Use prototyping to animate requirementsWrite a draft user manualPropose requirements test cases
J.Nawrocki, Requirements Review
Advanced guidelines
Requirements validation
Paraphrase system models
J.Nawrocki, Requirements Review
Summary
Requirements analysis: ChecklistsRequirements negotiationRequirements validation: Reviews & FTR (1028)
J.Nawrocki, Requirements Review
Questions?