"Tests for Effects" is a test type which allows tests to be created for defined failure effects (either design or object effects). This allows tests to be easily created for symptoms derived from imported FMECA data. In the diagnostics, the coverage for each “Test for Effect” is calculated as the root (lowest-level) failure mode causes of the associated failure effect.
Even if you do not include FMECA data in your models, this new test type provides a useful way to define upper-level test coverage in terms of failure modes in one or more lower-level models— without having to inherit (or re-inherit) tests hierarchically. In the past, tests with discrete, yet dispersed lower-level coverage would have to be modeled by creating tests in multiple lower-level designs, creating hierarchical tests at each higher level, and then grouping the final tests together at the top. Now, simply model the propagated effects of the root failure modes and then create one test at the top (in fact, to prevent the inefficient use of this new test type, you are prohibited from inheriting these tests hierarchically). Modifying test coverage is as simple as updating the list of causes for the appropriate failure effect (at any level of the design) and then saving hierarchically (if the effect is defined within a lower-level model).
To create tests for effects, click on the “New Test(s) for Effects” icon on the Test Set Editing toolbar. This icon, which appears immediately below the icon used to create Inspection tests, looks similar to the icon used to identify failure effects in eXpress (the only difference being that the red ‘E’ has been replaced with a ‘T’). This icon on the toolbar is used throughout eXpress to identify tests that are based on design effects; a similar icon (sporting a blue ‘T’) is used to identify tests based on object effects. When you click on this icon, the “Create Test(s) for Effects” dialog will appear.
Use the dropbox at the top of the dialog to select whether tests are to be created for design effects or object effects. Enable the checkbox beside each failure effect that you wish to test, and click on the Create button. A test will be created for each selected failure effect.
Click repeatedly on the “Change Tree Sort / Grouping” icon (immediately below the list of failure effects) to change the way in which failure effects are displayed: as an alphabetized list (as shown at right), as a set of folders that categorize failure effects by severity, or (for object effects) as a set of object folders that contain the effects associated with each object.
The test symmetry defaults to “Effect Implies Malfunction”, which means that the test is only meaningful when one of the covered failures occurs. You can change this setting on the Test Interpretation panel or in Grid View.
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