Project Management effects on software dependability

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Project Management effects on software
dependability

• Brendan Murphy
• Microsoft Research
• Cambridge, UK

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Agenda

• Developing solutions.
• Exploring dependability
• Ignored areas of dependability.
• Program Management of Windows NT (brief overview).

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Achieving highly dependable software programs.
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What went wrong
Not tested in Production environment.
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Apply other engineering disciplines to software
(e.g. trains)!

• Original problem.
• People had there own trains.
• Many different track designs.
• Variations in train design.

• Solution - redefined the problem
• Standardization.
• People training.
• 150 year of trial and error.
• Result a dependable but inflexible process.

Red for danger L.C.Rolt
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Developing dependable systems.

• Solution.
• Develop specialized hardware.
• Write your own OS and applications.
• Employ highly trained users and operators.
• Problems
• Very expensive.
• Difficult to get staff.
• Comparison to commercial products.

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Dependability requirementsbugs/KLOC?
Problem. Dependability needs.
Safety Critical Predictability.
Business Process. Knowledge transfer.
Database development. Data integrity.
New product. Very little.
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Overlooked dependability issuesSystem Recovery
of OpenVMS systems.
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Knowledge affects dependability.OpenVMS
dependability improvement over time.
System Reliability Issues, FTC 1999 Murphy, Davies
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Project Management at Microsoft.

• Ideal
• A standard predictable process producing
  dependable and secure software.
• Reality
• No ideal process exists.
• Development teams have flexibility in their
  development process.
• System test and release a separate process.
• Continuous tool development.
• User Interface a separate group.

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Windows NT development.
Legacy applications
New applications
Development Teams (e.g. kernel)
Release Management System Test Development System
Verification
Responsible for Design Implement Testing
New hardware and drivers
Legacy computer
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NT Development
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Summary

• Understand product dependability from the end
  user perspective.
• Assume you will not reach perfection.
• Understand the preferences/dislikes of the
  development team.
• Then choose the development and program
  management process.