Cumulative Lead Time

Cumulative lead time, unlike manufacturing lead time, includes the lead times for purchased items. It includes both the time to acquire purchased items and the time to complete the product.

Cumulative lead time is the number of workdays that are required to acquire items and complete a product, from its lowest-level components to the final item. Cumulative lead time is the level lead time for a product plus the longest cumulative lead time of any of its components. The cumulative lead time for a purchased item is its level lead time.

This graphic illustrates the calculation for cumulative lead time: