Explain in which cases the Replenishment Lead Time is considered by MRP according to the MRP type.
The reorder point MRP was configured to consider the requirements, e.g. order reservation from production order. Here is an example. The material TST_MATERIAL_004 has MRP type V1 and reorder point value 3 in the material master.
The material has procurement type F (External procurement), Purchasing processing time = 0 days, Planned delivery time = 28 days and GR processing time = 3 days. The total replenishment lead time is 31 days and was defined as explained in the blog post Calculation of the Replenishment Lead Time.
The current stock quantity is 0 and there is an order reservation quantity 6, inside of the replenishment lead time and a second order reservation quantity 10 outside the replenishment lead time.
In the customization OMDQ the field 'Include ext. reqmts' is set as '2 External requirements within the replenishment lead time'. In this case, the system does not include the customer requirement with a requirements date outside the replenishment lead time. In this example, when executing MRP the requirement quantity 6 will be covered, as well as the reorder point quantity 3, resulting in a proposal of quantity 9. However, the second requirement of quantity 10 will not be covered since it is out of the replenishment lead time.
Now, if the MRP type of material is changed to PD, the MRP create a proposal to cover all the requirements, which means that the replenishment lead time is not considered.
This type of planning is carried out for the quantities planned of any requirement that is MRP-relevant. In this type of net requirements calculation and its planning, the following statements apply:
The system doesn’t consider nor ask for any forecast information or historical consumption values. Material planning is ensured only on the basis of absolute requirements or demands in hand.
The system determines the available stock in the planning run, which is required to meet the demands, with the following logic:
Plant stock (+) scheduled receipts from production and purchase (–) all of the demands, for example, from sales order, material reservations, and PIR
If the available stock is unable to fulfill the demand, then depending on the settings of the planning run, it creates planned orders for in-house production as well as planned orders, delivery schedules/scheduling lines, or purchase requisitions for external procurement. Therefore, the RLT is not considered, as we can see in the customization: