When calculating available inventory, MRP considers the Available for Planning flag, Shelf Life Type, Expiration Date, and Planning Days Past Expiration of the associated serial/lot row.
If Available for Planning = N, the serial/lot quantity is excluded from available inventory.
If Available for Planning = Y with Shelf Life Type = Non-extendable
The process sorts serial/lot rows in ascending order of expiration date, and assigns them to demand in ascending order of need date. If inventory is expired, it cannot satisfy a demand with a later need date. Such time-phased approach will indicate how much of the demand can be met by material that is unexpired at the time of the need dates. Planned orders will be created for any shortages that still exist.
If Shelf Life Expiration Date >= Current Date, it will be included as available inventory for all demands with Need Date <= Shelf Life Expiration Date. Supply (in ascending expiration date order) is assigned to demand (in ascending need date order). If multiple serial/lot rows have the same expiration date, these are used in ascending order of their creation.
Any unassigned serial/lot quantity past its expiration date is excluded from further assignments, and is considered unavailable. Note that even though it is unavailable for the original part demand, it could still be available as a substitute part for another part’s demand with a need date <= expiration date.
If Available for Planning = Y with Shelf Life Type = Extendable
The process sorts serial/lot rows in ascending order of expiration date, and assign them to demand in ascending order of need date. If inventory is expired (adjusted for planning days past expiration), it cannot satisfy a demand with a later need date. Such time-phased approach will indicate how much of the demand can be met by unexpired material at the time of the need dates. Planned orders will be created for any shortages in supply.
If Number of Extensions Taken < Number of Extensions Allowed (If (Shelf Life Expiration Date + Planning Days Past Expiration) >= Current Date), it will be included as available inventory for all demands with Need Date <= (Shelf Life Expiration Date + Planning Days Past Expiration). Any unassigned serial/lot quantity past its Shelf Life Expiration Date + Planning Days Past Expiration is excluded from further assignments. Supply is assigned (in ascending expiration date order) to demand in ascending need date order. If multiple serial/lot rows have the same expiration date, these are used up in ascending order of their creation.
If Number of Extensions Taken = Number of Extensions Allowed, It will be included as available inventory for all demands with Need Date <= Shelf Life Expiration Date. Any unassigned serial/lot quantity past its Shelf Life Expiration Date will be excluded from further assignments. Note that even though it is unavailable for the original part demand, it could still be available as a substitute part for another part’s demand with a need date <= (Shelf Life Expiration Date).
If Plan Substitute Parts option is selected in the MRP settings, depending on the planning order of substitute parts, the process may use original or substitute parts to fulfill demand. Either way, the same rules apply.