In eXpress, test weightings are calculated (based on the defined weighting parameters) using the following three steps:
Each test weighting is first calculated by deriving a Test limit based on the entity, type, domain and best equals parameters in the corresponding weighting definition.
For each weighting, the Test limits derived for all tests are then mapped into a standard normal distribution. This normalization allows unlike weightings to be combined without worrying about differences in scale (for example, a relatively large failure rate may be a considerably smaller Test limit than a relatively small replacement cost).
Finally, the normalized Test limits for each test's weightings are multiplied by the Test limit defined in the priority parameter and then summed. The final result is a single weighting Test limit for each test.
