MRP Purchase Requisition date calculation

Hello,

I am working as an SAP Production Planning Consultant for the last 11 years.

This blog will be useful for people working in the areas of SAP Production Planning (PP) or SAP Material Management (MM) as this is a crossfunctional area.

Here I am trying to focus on one of the extensively used functionalities in SAP PP i.e MRP. As many of you know, MRP is a very complex algorithm developed by SAP to help the business in day-to-day planning activities. Even though MRP is a very widely used planning functionality, there is a basic lack of understanding of some of its features. This short blog is an attempt to throw some light on one of such features.

“What will the MRP consider when it is proposing dates for a purchase requisition?

MRP run will have 2 outputs i.e Planned orders (For in-house produced materials) and Purchase Requisitions (For externally procured materials). This blog will only focus on the purchase requisition part.

PURCHASE REQUISITION DATES:

First, let’s understand what are the key dates in the PR that we need to check.

  • Request date: The date on which the PR is created
  • Delivery date: The date on which the stock will be delivered to the plant by the vendor
  • Release date: The date on which the PO should be released to the vendor

Dates%20in%20the%20MRP%20generated%20PR

Dates in the MRP generated PR

FIELDS DETERMINING THE PR DATES:

There are 3 key values that determine the release date and delivery date of the PR.

  • Purchase processing time (PPT): (Plant level data-OMDT)
    No. of working days taken for release approvals and vendor communication – (Working days as per factory calendar)
  • Planned Delivery time (PDT): (Material master/PIR level data)
    No. of calendar days for the vendor to deliver the goods (7 days a week are considered)
  • GR processing time (GRPT): (Material master level data)
    No. of working days for activities after GR like QC clearance (working days as per factory calendar)

TEST CASE: Let’s understand the behavior of the system using a simple test case.

Data maintained: PPT: 1 day | PDT: 2 days | GRPT: 1 day

26 Sep – Requirement date (from production order/planned order/reservation, etc..)

Let’s assume that 24 and 25 Sep are not working days

23 Sep  – Delivery & GR processing (quality clearance).

  • If the requirement date falls on a non-working day, the system will propose the earliest possible working day of the plant and propose that date as the delivery date
  • If GRPT is not maintained, the delivery date will be the same as the requirement date 
  • The system considers that delivery and quality clearance/consumption (if no GRPT) can be done on the same day

21 Sep – Send/Release PO to Vendor

20 Sep – PR should be converted to PO automatically at the night (PO ready by morning)/manually by business users as per their requirement

  • For automation, the PR to PO conversion batch job should be scheduled by the MM/Sourcing team after the daily MRP job

FEW OTHER SETTINGS:

  • Purchasing default values for MRP (OMDT): If the below-highlighted indicator is set in OMDT, then the system checks whether a planned delivery time is entered in the purchasing info record or in the outline agreement. This planned delivery time is then used to calculate the delivery date and the release date. If you are going to maintain the PDT in PIR, make sure you maintain a source list that is MRP-relevant.

  OMDT%20configuration%20setting

OMDT configuration setting

  • Safety time: Technically safety time will not directly impact the delivery date, but it only pushes the requirement date to an earlier date on the time axis which will be followed by regular calculation as explained above. If safety time is maintained (work days), the requirement date will be brought forward on the time axis by the number of workdays you define here. The “Safety time indicator” can be maintained as 1 or 2 based on the scenario.

Safety%20time%20in%20MRP%202%20view

Safety time in MRP 2 view

Conclusion: By now, you will be able to analyze the dates of the PR created by the MRP. This blog has only covered the typical MRP PR scenario, but I hope this helped you to understand the functionality better.

Please add your suggestions/feedback in your comments section.

Related links:

MRP tag – https://blogs.sap.com/tags/320517996275254407406398077757010/

MRP Planning process – https://blogs.sap.com/2019/11/20/mrp-planning-process/

https://answers.sap.com/questions/9663085/mrp-run-and-pr-release-date.html

Thanks,

Krishna Chandra