Computer-Aided Software FMEA

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Computer-Aided Software FMEA
Herbert Hecht, Xuegao An and Myron Hecht SoHaR
Incorporated Culver City CA 90230
MDES Washington DC 27 May
2003
Research supported by the DARPA MoBIES Program
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FMEA as a VV Tool
VV TARGETED AT AREA OF VULNERABILITY
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Problems with Software FMEA

• No Parts List
• Use Functional FMEA
• Where are the functions defined?
• Is all exception handling in the specification?
• No Completion Criterion

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UML-Based Software FMEA

• Methods Parts
• Get Methods from Class Lists
• Closely Coupled to Generated Code
• Facilitates Completion Criterion

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Computer-Aided Approach
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Analyst Screen Example
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Assigning Failure Effects

• System and NHL Effects defined by System or
  Project Management
• Propagation Paths defined from Collaboration
  Diagram
• Propagation of Effects depends on Protective
  Programming Practices (assertions, time-outs,
  check points)

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Effect of Corrupted Input
Detection Compensation NHL Effect
None Crash
Detection Only Stop
Detection Re-Try Delayed Output
Detection Default Value Degraded Output
Alternate Method None
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Benefits Of Computer Aided FMEA

• Reduced Labor Requirement
• Less Subjective (Method vs. Function)
• Focus on Protective Programming
• Improved Support of VV