Team Skill 6 - Building The Right System Part 2: Traceability, Change and Quality (Chapters 27-29 of the requirements text)

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Team Skill 6 - Building The Right SystemPart 2
Traceability, Change and Quality(Chapters 27-29
of the requirements text)
Traceability in the US food supply, from
http//www.ers.usda.gov/Briefing/Traceability/over
view.htm

• CSSE 371 Software Requirements and Specification
• Don Bagert, Rose-Hulman Institute of Technology
• October 11, 2005
• Thanks to Mark Ardis and Steve Chenoweth for some
  of the slides included.

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Outline

• Tracing Requirements
• Managing Requirements
• Assessing Requirements Quality

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Tracing Requirements
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Traceability Primary Questions

• Why is tracing important?
• What mechanisms are used for tracing?

Why we care remember this triangle?
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Traceability The Problem

• How do you know, if youre at one of these later
  stages, that you have a requirements fault?

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In general, how to trace
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With use cases, for instance
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Managing Requirements
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Managing Change Primary Questions

• How do you capture change requests?
• How do you respond to these (individually
  overall)?
• How does this tie-in with tracing requirements?

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A Process for Managing Change 1/3
Step 1 Recognize that change is inevitable, and
plan for it
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A Process for Managing Change 2/3

• Step 2 Baseline the requirements
• This means they are signed-off on, and
• From then on, they fall under change control
  see below

• Step 3 Establish a single channel to control
  change
• No ad hoc additions
• No ad hoc fixes, either

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A Process for Managing Change 3/3
In ? this big picture, you especially need to
know what release management ? is!
Step 4 Use a Change Control System to Capture
ChangesStep 5 Manage Change Hierarchically
Figure on middle right from http//www.debian.org/
vote/2002/platforms/raphael
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Assessing Requirements Quality
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Quality Issues

• Products vs. Processes
• Review Methods
• Checklists

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Products vs. Processes

• Organizations that produce high-quality products
  invest in high-quality processes.
• Product quality can be measured through testing.
• How can we measure process quality?

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Review Methods

• Informal
• Ask a peer to read and give comments
• Formal
• Ask a peer to prepare for review
• Record and report results of review
• Active
• Interrogate reviewer

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Checklists

• Look for anticipated defects
• Some defects apply to almost all artifacts
• Does the artifact exist?
• Some defects are artifact-specific
• Have you identified all stakeholders?

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Problem Statement Checklist

1. Has a problem statement been drafted?
2. Is it written in an easy-to-understand way?
3. Does the team understand it?
4. Has it been circulated for agreement to the key
   stakeholders, including management?
5. Do the team members have agreement that this is
   the problem they are trying to solve?

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Supplementary Specification Checklist (1/2)

1. Have you established an appropriate template?
2. Are all non-functional requirements included in
   the supplementary specification?
3. Have requirements for usability, reliability,
   performance and supportability been captured?

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Supplementary Specification Checklist (2/2)

1. Have design constraints been identified?
2. Have supplementary requirements been linked to
   use cases where appropriate?