Design and Code Inspections to Reduce Errors in Program Development'

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Design and Code Inspections to Reduce Errors in
Program Development.

• M.E. Fagan
• IBM Systems Journal, 1976
• Presented by
• Ankush Varma

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Overview

• What is Code Inspection
• Study Quantification of Benefits
• The Formal Inspection Process
• Code Inspection for Process Management

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Code Inspection

• Code is only looked at from a debugging
  viewpoint.
• Cannot revisit algorithms, check for coding
  standards etc. easily.
• Inspection is a formal process of looking at all
  aspects of both design and code even when nothing
  seems broken.

Write Code
Debug
Test
Add features
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Programming A Manageable Process

• Programming can be though of as a process
• Requirement Statements are Input.
• A series of processing operations act on this.
• Each step has well-defined output.
• Each step has unambiguous exit criteria e.g.
  clean compilation, number of lines of code a
  design statement translates to etc.
• Cost of reworking errors massively increases down
  the process.
• Note the underlying ties to a waterfall model.

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The Programming Process
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The Benefits of Code Inspection A Study
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Study of Error Detection Rates
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The Formal Inspection Process
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People Involved

• Moderator
• Designer
• Coder/Implementor
• Tester

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The Steps of the Inspection Process
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What to Look For Examples
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Code Inspection for Process Management
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Using Code Inspections for Process Control

• List most error-prone modules to prioritize
  testing, re-coding or later inspections.
• Compare processes to evaluate relative
  effectiveness.
• Use increased predictability to plan ahead.
• Error re-work moved to first half of process,
  where it is cheaper.
• Earlier quantification of product quality.

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Inspections are NOT Walk-Throughs
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Questions/Discussion