Firm Planned Order Rescheduled by MRP

[Former Member]

Hello All,

We have experienced firm planned orders being rescheduled by MRP on a limited number of materials in our system.  This does not happen to all materials and we have not been able to duplicate the behavior in our test client.  We can see nothing obvious that is different between one material or another.  The scenario is that the client generates demand through firm planned orders and not planned independent requirements.  They are linked to an external demand planning system and that system does not like it when SAP moves these orders around.  We see the rescheduling on past due firm planned orders.  MRP is run and the past due order is rescheduled for today.  Like I mentioned, this only happens for a limited number of materials.  On the majority of the parts, we run MRP and the firm planned order in the past stays in the past.  On these parts, MRP is run and the past due firm planned order is moved to today's date.  This happens when using planning mode 2, not planning mode 1, if that sheds any light. 

We are in a REM environment on HANA.

Eric

[Caetano · Accepted solution]

Hi Eric

Can you please provide more details?

Is MRP changing the basic or the production dates?

If you don't want to have the production dates changed by MRP, maybe you could change your settings on OPU5.

BR

Caetano

[Former Member · Accepted solution]

Caetano,

Thank you for the quick reply.

I am sorry, but I don't have those details.  The situation is only there to study for a brief amount of time.  We are told this is happening on multiple materials.  Enough materials that this is a hot button issue.  I was able to work with the one part I could find last night because MRP ran before midnight and when we passed midnight and ran MRP on the item, it rescheduled forward.  I may or may not have that chance on this part or another part tonight.  The planned orders on this item from last night were already produced this morning.

I could change my settings on OPU5, but is still doesn't answer the question of why some materials and not others.  I'd like to understand that, because we may have another problem somewhere else.  I have plenty of examples of planned orders that do not reschedule when MRP runs.  This should be standard SAP behavior unless I am mistaken.

If I am able to answer your question after some further testing, I'll post the results.  Thanks again.

[Former Member · Accepted solution]

Tonight there were 17 materials in Plant A with planned orders due yesterday.  I ran MRP on all 17 materials and 8 out of 17 planned orders rescheduled from yesterday to today.  This is a higher hit rate than I was expecting.

I ran with MRP settings NETCH 1 3 1 2 2.  When MRP was run with NETCH 1 3 1 1 2, the planned orders did not reschedule.

I took before and after screen shots of all the tabs on the planned order and found that both the Basic and Production dates moved out one day from January 31 to February 1.  The MRP Availability Date moved one day also.  None of the other information on this tab or the Assignment or Master Data tabs changed.  The BOM explosion date did not change.  The Detailed Scheduling tab changed to the new dates as one would expect.

Once again, these are REM orders.

Those are the details as I know them.

[Former Member · Accepted solution]

Eric,

As mentioned by expert Almeida, you probably have your basic dates tied to your scheduling dates in OPU5.  One way to prevent this would be to change configuration in OPU5 such that the basic dates are not to be affected by scheduled dates.

If this is not acceptable, you might want to increase the OPU5 "Start in the past" value.

They are linked to an external demand planning system and that system does not like it when SAP moves these orders around.

Since you seem to want the external system to retain control of these orders, another option might be to turn scheduling off altogether for these orders.  Create a control key for the Routing steps that does not include scheduling, and then have the external system control the start and end dates.

Best regards,

DB49

[Caetano · Accepted solution]

Hi Eric

If the planned order basic date was change by MRP, I don't think that they were firmed.

As already pointed here, if there is an external system scheduling the orders, I believe that scheduling on the MRP should be turned off, to avoid this kind of issue.

BR

Caetano

[Former Member · Accepted solution]

Both of you suggested OPU5 and that's where we found some immediate relief, but not 100% of the answer.  Adding days to the "Start in Past" setting allowed the planned orders to remain in the past, but not all of them.  Our client wanted orders that were past due to remain past due and this solved 98% of that problem.  Thanks for the recommendation.

We can't go to an MRP type for planning by an external system.  That code is used by something else (GATP?) in our set-up and is shared by materials for which this scenario does not apply (purchased parts).

The firming indicator was set on these orders both in the planned order and in the PLAF table.  Maybe I don't understand what firming is, but I thought the basic and production dates were frozen from MRP until someone manually made a change or removed the indicator. 

We have basic dates in December with production dates in February (Is that normal?).

We have other quirky behavior occurring in the MRP area and I have several incident messages open with SAP at this point.  One to cover this and another for MRP Lists generated, materials not planned.

Thanks again.  It's great to have a place where people can provide answers to these questions.

[Former Member · Accepted solution]

Eric,

We can't go to an MRP type for planning by an external system.  That code is used by something else (GATP?) in our set-up and is shared by materials for which this scenario does not apply (purchased parts).

???  I don't think anyone suggested this.  The suggestion was to disable scheduling.  FYI orders that are firmed are not automatically exempted from scheduling/rescheduling.

We have basic dates in December with production dates in February (Is that normal?).

Well, it is an indication that your plan doesn't match with reality.  Plans that don't match reality are definitely possible, but this situation is what planners work to avoid, and to correct when possible.  So, that being said, yes, it is normal.  The perfect plan never really exists, it is only a goal; an intellectual exercise.

Best Regards,

DB49

[Former Member · Accepted solution]

'...an intellectual exercise.'  I got a kick out of that.  An intellectual exercise it is.