During the maturation of the diagnostics, tests are best created in sets that represents types of testing. In this way, a test set will typically contain a group of similar tests like Initiated BIT. This grouping of tests is what enables simple diagnostic trade studies.Incorporating Prognostics into the diagnostic approach requires understanding of a few basic principles:
- Prognostics can't increase Detection Coverage
- Prognostics can reduce ambiguity
- Prognostics can detect failures before they occur
- Prognostic Tests can detect failure before Diagnostic Tests
Therefore, we can conclude that as we add Prognostics, our detection percentage should remain the same. What we will hope for is detection before a critical failure, or fault isolation to a smaller fault group.
To add Prognostic knowledge to the design, the problem is broken into two parts:
- Trend Analysis and Prediction
- Detection of Impending Failure