软件质量调查2010年（美国版）.ppt

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * SOFTWARE DEFECT POTENTIALS AND DEFECT REMOVAL EFFICIENCY FOR EACH LEVEL OF SEI CMM (Data Expressed in Terms of Defects per Function Point For projects nominally 1000 function points in size) Defect Removal Delivered SEI CMM Levels Potentials Efficiency Defects SEI CMMI 1 5.00 80% 1.00 SEI CMMI 2 4.00 90% 0.40 SEI CMMI 3 3.00 95% 0.15 SEI CMMI 4 2.00 97% 0.08 SEI CMMI 5 1.00 99% 0.01 SEI CMMI 6 (TSP/PSP) 1.00 99.5% 0.01 SOFTWARE DEFECT POTENTIALS AND DEFECT REMOVAL EFFICIENCY FOR EACH LEVEL OF SEI CMM (Data Expressed in Terms of Defects per Function Point For projects 5000 function points in size) Defect Removal Delivered SEI CMM Levels Potentials Efficiency Defects SEI CMMI 1 5.50 73% 1.48 SEI CMMI 2 4.00 90% 0.40 SEI CMMI 3 3.00 95% 0.15 SEI CMMI 4 2.50 97% 0.008 SEI CMMI 5 2.25 98% 0.005 SEI CMMI 6 (TSP/PSP) 2.00 99% 0.004 Defect Removal Efficiency Defectsper FP Malpractice U.S. Average Best in Class . ? ? MAJOR SOFTWARE QUALITY ZONES SEI CMM 2 SEI CMM 3 SEI CMM 4 SEI CMM 5 TSP/PSP The SEI CMM has overlaps among the levels. INDUSTRY-WIDE DEFECT CAUSES 1. Requirements problems (omissions; changes, errors) 2. Design problems (omissions; changes; errors) 3. Interface problems between modules 4. Logic, branching, and structural problems 5. Memory allocation problems 6. Testing omissions and poor coverage 7. Test case errors 8. Stress/performance problems 9. Bad fixes/Regressions 10. Documentation errors Ranked in order of effort required to fix the defects: OPTIMIZING QUALITY AND PRODUCTIVITY Projects that achieve 95% cumulative Defect Removal Efficiency will find: 1) Minimum schedules 2) Maximum productivity 3) High levels of user and team satisfaction 4) Low levels of delivered defects 5) Low levels of maintenance costs 6) Low risk of litigation INDUS