Test-Fix-Test Data (Failure Terminated) Reference Example

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Test-Fix-Test Data (Failure Terminated) Reference Example

This example validates the results for test-fix-test data (failure terminated) in RGA.


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
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)
  • 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 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:
IEC 61164 Example 1 - Case 2 Results.png


  • The Cramér-von Mises goodness-of-fit test result:
IEC 61164 Example 1 - Case 2 Stat Tests.png


  • 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.
IEC 61164 Example 1 - Case 2 QPC.png