Test-Fix-Test Data (Failure Terminated) Reference Example
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This example validates the results for test-fix-test data (failure terminated) in Weibull++ Reliability Growth data folios.
Reference Case
International Standard IEC 61164 (Reliability Growth in Product Design and Test – Statistical Test and Estimation Methods), Example 2 – Case 1, 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 |
Result
The book has the following results:
- Beta(UnB) = 0.5594, Lambda = 1.1067
- CL = 0.9 (two-sided confidence bounds on DMTBF)
- DMTBFUpper = 46.7 hours
- DMTBF = 33.5 hours
- DMTBFLower = 24.3 hours
- CVM = 0.041, critical value = 0.173. Since CVM < critical value can fail to reject hypothesis that the model fits the data.
Results in Weibull++
In Weibull++, the Crow-AMSAA (NHPP) model with the maximum likelihood estimation (MLE) method was used to calculate the results.
- The model parameters are:
- The Cramér-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.
