CTP : Surplus situation created with planning event "Cover Dependent require immediately"

[Former Member]

Hi All,

Our business has implemented CTP so that they can do constraint planning in PPDS. In our scenario material is the only constraint. We are not finitely scheduling the resources with CTP planning and hence the Finite scheduling indicator is set off. So currently we do run lot sizing heuristics once and after that the planning situations keeps on changing when a new sales orders is introduced or a sales order is converted into delivery or someone tried to reschedule the production orders.

Issue : For the purchase components we are using a periodic lot size with same qty in Min and Max lot size because we need a receipt with a fixed qty.for e.g. Min and max set to 41888 LB .

The lot sizing heuristic consider the lot size settings create the proposals correctly in system. Now when a new sales order is introduced in system , it runs an ATP check at all the BOM levels and there are some cases where the dependent demands are shifted from current date to future date(Forward scheduling) or CTP has created new receipts at header or deleted the receipts at header. In that case it creates new proposals additionally which create lot of surplus for the purchase components.During the business hours it creates lot of extra receipts which is not needed.

Current system settings

Planning Procedure is set to "S" for all the products starting from header to components. The heuristics maintained at the planning procedure level is standard CTP heuristics SAP_PP_CTP.

Events - Creating or changing the receipt element of an in-house production order.

Action - Cover dependent/stock transfer requirements immediately with existing receipts.

For any changes in sales orders the action is to start the product heuristics immediately.

Questions

1. Is this the standard behavior of CTP ?

2. Is there a way I can reduce the surplus without affecting the CTP planning ?

3. How does peirodic lot size affects the planning since the event "Cover dependent requirements immediately" do not consider the periodic lot size.

[rupesh_brahmankar]

Hello,

Please refer SAP note 426563 - CTP: Settings, system behavior and performance (docu)

Question 6 -Can a periodic lot-sizing procedure be used in a CTP process?

Periodic lot-sizing procedure is characterized by a new additional requirement in a period causing an increase in planned order quantities. This invariably causes a lengthening of the order lead time of the one planned order of the period thereby causing the dependent requirements dates to be brought forward. With periodic lot sizes there is therefore the risk that after the arrival of a new requirement, customer orders that have already been confirmed are confirmed against a schedule that is no longer possible. Periodic lot-sizing procedures can therefore not be used in a CTP process. This restriction also applies to multi-level ATP. See also Note 455421

You may use the heuristic SAP_PP_003 at component level to reducing surplus quantities

Best Regards,

R.Brahmankar