3. Maintainability forecasts

Maintainability forecasts should be undertaken during the product design phase, as soon as information on the averages of corrective and preventive maintenance times for components, derived from reliability studies, becomes available, and plausible estimates of maintenance times and their statistical distributions for the different types or modes of component failure are made.

It's at this point in the project's development that forecasts are most useful, since it will then be possible to reveal any shortcomings and modify the project before the prototypes are built.

In what follows, it will be assumed that system maintenance is steady-state, and that corrective λ _c and preventive λ _p renewal rates can be assumed constant. Systems are assumed to...