MRP - firming Purchase Order dates for MRP run

[Former Member]

We are using demand management and MRP to create purchase requisitions for external procurement. It works fine and creates purchase requisitions based on the monthly demand entered in MD61. However, if I have a purchase order with a delivery date of a few months in the future, MRP always asks me to reschedule the order to meet current demand. i.e. it reduces the quantity on a requisition because it expects the rescheduled PO to meet the demand. In addition, it creates a requisition for the full demand a few months out, even though I have a PO delivery on that date (as it expects me to move the PO to the current date) See example below

Does anyone how to get MRP to treat a PO delivery date as fixed or firmed and create requisitions based on this?

We are using MRP type PD, a planning strategy that looks only at LSF in demand management and KSL in SD requirements.

Thanks

Donal

Scenario:

Current Stock: 500 KG

Safety Stock Level: 1000 KG

Demand:

Aug: 1500

Sep: 2000

Oct: 3000

PO del date 01.10.08 : 750 KG

When I run MRP it proposes the following

01.08.08 Requisition: 1250 KG. Aug demand (1500) + deficit below safety stock (500) = 2000 less PO that it is saying I should move to July (750). (I want this qty to be 2000)

01.09.08 Requisition: 2000 KG. Sep demand (2000) - OK

01.10.08 Requisition: 3000 KG. Oct demand (3000). Doesnu2019t look at PO dated 01.10 at all. (I want this qty to be 2,250)

[Former Member]

OMDW

rescheduling horizon days fixes this.