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Test-Fix-Test Data (Failure Terminated) Reference Example
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This example compares the results for test-fix-test data (failure terminated).
Reference Case
International Standard IEC 61164 (Reliability Growth in Product Design and Test – Statistical Test and Estimation Methods), Example 1 – Case 2, pg. 30.
Data
The following table shows the data.
2
|
4
|
10
|
15
|
18
|
19
|
20
|
25
|
39
|
41
|
43
|
45
|
47
|
66
|
88
|
97
|
104
|
105
|
120
|
196
|
217
|
219
|
257
|
260
|
281
|
283
|
289
|
307
|
329
|
357
|
372
|
374
|
393
|
403
|
466
|
521
|
556
|
571
|
621
|
628
|
642
|
684
|
732
|
735
|
754
|
792
|
803
|
805
|
832
|
836
|
873
|
975
|
Termination Time = 975 hours
Result
The book has the following results:
- Beta(UnB) = 0.5594, Lambda = 1.1067
- CL = 0.9 (two-sided confidence bounds on DMTBF)
- CVM = 0.041, critical value = 0.173. Since CVM < critical value can fail to reject hypothesis that the model fits the data.
Results in RGA
In RGA, the Crow-AMSAA (NHPP) model with the maximum likelihood estimation (MLE) method was used to calculate the results.
- The model parameters are:
The Cramer-von Mises goodness-of-fit test result:
- The instantaneous MTBF and its two-sided 90% confidence intervals are shown next. The confidence bounds in the QCP are calculated using Crow Bounds methodology.