TRAX MANUALS > Settings > Settings Module > Settings, Update Menu > P/N (Part Number) > P/N Master Buttons > P/N Control Button, via P/N Master > Setting Up a Prorated Part > Seamless Prorated Part Formula Used in Planning

A part can be used in multiple service applications throughout its life (i.e. installed on different aircraft types/series, or in different assemblies) and therefore it will have different life limits (i.e. P/N Controls) for each of its service applications. These parts are set-up as prorated parts in the P/N Master.

A prorated calculation of the life consumed (i.e. sum of the fractions of accrued life) during the part's previous service applications is used to determine the remaining life in its current service application.

The prorated calculation is used only in the planning module and only for a part that is currently in service on an aircraft. It is not used for parts that are in the inventory.

The prorated calculation is done automatically by the Trax System using the following formula:

Where:

X = life remaining for the current service application.

åAn/Bn = sum of the fractions of accrued life from service applications.

A = time accrued in service application (n)

B = life limit in service application (n)

H = life limit for current service application.