The "Two Engine Model" for Software Quality Measurement and Improvement

1. The "Two Engine Model" for Software Quality Measurement and Improvement A lively romp through process capability, documentation, and measurement without getting your feet wet. By Tom Gilchrist SASQAG, Aug 2011

2. Disclaimer • The views and opinions in this presentation are my own and do not necessarily reflect those of my employer…. • Context is everything…your mileage may vary. • If you don’t try something different, don’t be surprised that the outcome doesn’t change!

3. Communication with an engineering is only a little more difficult than communication with the dead.

4. Tonight... • Some Context • Feedback Systems • Change or Improvement?

5. Some Definitions…. • Process: How we remember things that work, so we can repeat them. How we remember things that don’t work, so we can avoid them. • Errors, Defects, Faults, and Failures • Error: a human action or mistake that results in the SW containing a defect. (MEWU) • Defect: a Fault that exists in the software, which if not corrected, could cause the software to fail or produce incorrect results • Failure: An occurrence of the SW not meeting its requirements or intended usage while it is being executed.

6. Quality Measurement Areas Pre-Development Errors Requirements Change Board Subs COTS Design Development Errors/Defects Coding Dev Tests Int Tests Pre-Release Failures Acceptance Post-Release Failures Production

7. Quality Measurement Areas Escape Rates, Efficiency & Effectiveness Pre-Development Errors Requirements Change Board Subs COTS Design Development Errors/Defects Coding Dev Tests Int Tests Pre-Release Failures Acceptance Post-Release Failures Production

8. Understanding Rework Productivity People Quality Work Being Done WORK TO BE DONE WORK REALLY DONE Why is rework bad? KNOWN REWORK UNKNOWN REWORK Rework Discovery *From IEEE Engineering Management Review, Winter 1994

9. Single Engine Model Business Objectives & Constraints Trigger CONTROL CYCLE Usage Results ACTION MEASUREMENT Entry Criteria Exit Criteria Internal PROCESS Needs & Constraints Deliverables

10. Two Engine Model Maintain and Improve the Process Results Lessons Learned Organization Professional Practices Projects Use the Process