total replacement time
The total replenishment time is the time required to make a specific material or end product fully available again, starting from a demand event, across all relevant procurement and manufacturing stages.
It typically comprises the sum of internal planning and lead times (e.g. demand determination, order release, in-house production times) as well as external planned delivery and transport times along the longest or critical path of the bill of materials. In many ERP systems, this time is recorded as a separate parameter in the material master and serves as the basis for planning, scheduling and availability checks to ensure that orders and production orders are triggered in good time so that the material is available on the required date.
In ERP systems, the total replenishment time is used to calculate realistic delivery dates during the availability check (ATP); requirements outside this time frame can be automatically confirmed as deliverable because it is assumed that the planning department will be able to replenish the stock by then.
Our tip:
Buffer and approval times are sometimes forgotten when determining the total replacement time. If they actually occur in the process, they must also be taken into account.
The longest total replenishment time for a range of items is an important benchmark for determining reasonable planning horizons, e.g. for material requirements planning, and check horizons, e.g. for availability checks.
