The tell-tale sign was
the large number of Open Critical and High bug reports in Figure 8.23. This told of a persistent inability
FIGURE 8.21 Overall bug detection profile
FIGURE 8.22 Open and closed critical bug reports
3000
Open and closed SCRs in version 4
2800
2600
2400
2200
2000
1800
1600
1200
1000
800
600
400
200
0
Open Closed
28 Mar
11 Apr
25 Apr
09 May
06 Jun
04 Jul
20 Jun
23 May
18 Jul
01 Aug
15 Aug
29 Aug
1400
3000
2800
2600
2400
2200
2000
1800
1600
1200
1000
800
600
400
200
0
Critical and high SCRs found and ?¬?xed in version 4.0
28 Mar
11 Apr
25 Apr
09 May
06 Jun
04 Jul
20 Jun
23 May
18 Jul
01 Aug
15 Aug
29 Aug
1400
Allegedly-?¬?xed Open Other Resolved Series ???Open???
Value: 174
Test Documents 147
to fix bugs without raising more. This habit was even more evident in Figure 8.24 where the number of
bug reports raised fluctuated greatly but the proportions remained steady. An improving system would
show an increasing proportion of lower-severity bug reports being raised. This didn??™t.
FIGURE 8.23 Build quality profile expressed as an absolute
FIGURE 8.24 Build quality profile expressed as a proportion
200 250 300 350 400 150 100
Critical High Medium Low
50 0
13 4 32
40 87
Bug severity and number by drop
44 11
155 93
17 37
62
66
60
48 78
62 53
27
13 48 33 4
47 35 30
49 1
22 1
23 7
0
91 31 5
61 28 3
91 28 4
136
77 17
12
11
10
9
8
7
6
5
4
3
2
1
124
Critical High Medium Low
0% 20% 40% 60% 80% 100%
13
Bug criticality per drop expressed as a percentage
12
11
10
9
8
7
6
5
4
3
2
1
148 Manage Software Testing
8.
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