SLIDE 7 7
24/4 - 17 Programvaruteknik - Jonny Pettersson, UmU
An Example
50% 15 8 7,5 7,5 1
Requirements inspection
50% 35 7,5 72 64 21,3 3
Design inspection
50% 30 21,2 328 256 25,6 10
Unit test
50% 10 25,6 862 534 17,8 30
Integration test
50% 10 17,8 1279 417 13,9 30
System test
100% 0 13,9 4059 2780 13,9 200
Operation Review, individual (40%,2) + Formal inspection, team (70%,5)
24/4 - 17 Programvaruteknik - Jonny Pettersson, UmU
An Example (cont.)
50% 15 8 7,5 7,5 1
Requirements inspection
40% 35 7,5 42 34 17 2
Design reviews
70% 25,5 132 90 17,9 5
Formal design inspection
50% 10 18,8 752 432 14,4 30
Integration test
50% 10 14,4 1118 366 12,2 30
System test
100% 0 12,2 3558 2440 12,2 200
Operation
50% 30 7,6 320 188 18,8 10
Unit test 13,9 4059
Fewer defects to lower costs!!!
Old QA plan
24/4 - 17 Programvaruteknik - Jonny Pettersson, UmU
High Variation in Defect Removal Effectivity
- Individuals testing their own code
− Usually < 50%
- Normal testing activities
− Often < 70%
- Design- and code inspections
− Often > 65%, up to 85%
- Formal inspections plus formal testing activities
− Often > 96%, up to 99%
- Formal inspections can lead to up to 30% decreases in
costs and lead times
