Requirements Verification

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Requirements Verification Validation
Requirements Engineering Project
Management Lecture 9

• Jerzy.Nawrocki_at_put.poznan.pl
• www.cs.put.poznan.pl/jnawrocki/require/

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XPrince Roles and VV
Project Manager
Auditor
Time
Time
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XPrince Artefacts and VV
Aim Scope
Business Model and System Scope
AS Plan
Most Important Use Cases
Architect. Vision Tools
Init. Project Plan
Architecture
Requirements Spec.
Initial Prototype (code test cases)
Architect. Plan
Mockup
Accept. Tests Frame
GUI Design
Updat. Proj. Plan
Project Manager
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Bibliography

• X

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Agenda

• Requirements Analysis Negotiation
• Requirements Validation
• Capture Recapture

• Introduction
• XPrince Team
• Project Lifecycle
• The Analyst Role
• The Architect Role
• The Project Manager Role
• Scaling up
• Conclusions

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Agenda

• Requirements Analysis Negotiation
• Requirements Validation
• Capture Recapture

• Introduction
• XPrince Team
• Project Lifecycle
• The Analyst Role
• The Architect Role
• The Project Manager Role
• Scaling up
• Conclusions

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Requirements Analysis and Negotiation
The requirements document
Requirements elicitation
Reqs analysis negotiation
Describing requirements
System modelling
Requirements validation
Requirements management
RE for critical systems
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Basic guidelines

• Define system boundaries

• Process requirements
• System requirements
• Software requirements

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Basic guidelines

• Define system boundaries
• Use checklists for requirements analysis

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A Checklist Example
Analysing systems boundaries

• 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?

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Another Checklist Example
a) Correct b) Unambiguous c) Complete d)
Consistent e) Ranked for importance and/or
stability f) Verifiable g) Modifiable h)
Traceable.
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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?
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Basic guidelines

• Define system boundaries
• Use checklists for requirements analysis

Provide software to support negotiations Plan for
conflicts and conflict resolution Prioritise
requirements
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Intermediate guidelines

• Classify requirements using a multidimensional
  approach

System, User interface, Database, Communications,
Security
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Intermediate guidelines

• Classify requirements using a multidimensional
  approach

System, User interface, Database, Communications,
Security
Use interaction matrices to find conflicts and
overlaps
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Advanced guidelines

• Assess requirements risks

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Agenda

• Requirements Analysis Negotiation
• Requirements Validation
• Capture Recapture

• Introduction
• XPrince Team
• Project Lifecycle
• The Analyst Role
• The Architect Role
• The Project Manager Role
• Scaling up
• Conclusions

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Requirements Validation
The requirements document
Requirements elicitation
Reqs analysis negotiation
Describing requirements
System modelling
Requirements validation
Requirements management
RE for critical systems
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Basic guidelines

• Check that the requirements document meets your
  standard
• Organise formal requirements inspections

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Reviews and Inspection

• Review Analysis of an artefact (e.g. code,
  document) done by 1 or more people.
• Goals of review
• Quality assurance
• Knowledge dissemination

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FTR Procedure
FTR Formal Technical Review
(Formalny przeglad techniczny)

• Producer (author)
• Project Manager
• Facilitator
• Reviewer(s)
• Recorder

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FTR Procedure

• 1. Producer advices the Project Manager
  Facilitator that the artefact is ready and sends
  them a copy.
• 2. Facilitator contacts all the inspection
  participants and decides about the date and time
  of the meeting (the sooner the better). He also
  sends the artefact to the reviewers.

3. Facilitator writes the agenda for the
meeting. 4. FTR meeting 5. Recorder prepares
inspection report and sends it to the
participants. A copy of it goes also to the
Project Manager.
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FTR Meeting

• Facilitator Presents the agenda. The
  participants may propose changes.
• Recorder Collects copies of the preparation
  forms.
• Producer Presents the artefact. Reviewers may
  ask questions. Recorder takes notes (issues and
  defects).

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FTR Meeting

• Recorder Summerizes the issues and defects.
• All participants except the producer Initial
  secret vote.
• Recorder Collects the votes and presents the
  result.
• Producer Last word
• All the participants except the producer Final
  secret vote.

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FTR Meeting

• 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.

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Agenda

• Requirements Analysis Negotiation
• Requirements Validation
• Capture Recapture

• Introduction
• XPrince Team
• Project Lifecycle
• The Analyst Role
• The Architect Role
• The Project Manager Role
• Scaling up
• Conclusions

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Capture-Recapture
How many fish are there?
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Capture-Recapture
1 Catch a sample
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Capture-Recapture
1 Catch a sample 2 Tag them
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Capture-Recapture
1 Catch a sample 2 Tag them 3 Release them
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Capture-Recapture
1 Catch a sample 2 Tag them 3 Release them 4
Catch another group
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Capture-Recapture
1 Catch a sample 2 Tag them 3 Release them 4
Catch another group 5 How many tagged?
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Capture-Recapture
1 Catch a sample 2 Tag them 3 Release them 4
Catch another group 5 How many tagged?
20
30
5
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Capture-Recapture
Total 20 30 / 5 120
1 Catch a sample 2 Tag them 3 Release them 4
Catch another group 5 How many tagged?
20
30
5
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Capture-Recapture
C
Total defects A B / C
If C 0 ...
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Capture-Recapture
More than 2 reviewers
Most unique defects found
All others
Total defects A B / C
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Basic guidelines

• Check that the requirements document meets your
  standard
• Organise formal requirements inspections

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Use multidisciplinary teams to review
requirements Define validation checklists
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Intermediate guidelines

• Use prototyping to animate requirements
• Write a draft user manual
• Propose requirements test cases

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Advanced guidelines

• Paraphrase system models

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Summary
At last!

• Requirements analysis
• Checklists
• Requirements negotiation
• Requirements validation
• Reviews FTR
• Capture-Recapture
• Mockups

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Questions?
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Quality assessment

• 1. What is your general impression? (1 - 6)
• 2. Was it too slow or too fast?
• 3. What important did you learn during the
  lecture?
• 4. What to improve and how?