Heuristics creates duplicate planned orders

[former_member476084]

Hi Gurus,

We have recently changed our phantom BOM's to Manufactured assembly BOM. Currently the heuristics running for the assembly components is the copy of standard lot sizing heuristics and only difference is the resuse mode we are using.We are deleting the unfirmed receipts and recreating again.

Many of the time for the assembly components have the order reservations in the past so when heuristics tries to cover the past demands it creates all all the new planned orders on the current date.Our production planners don't want the planned orders number should change in the next planning run.So to avoid deletion of existing planned order they "Date fix" the planned orders.We are fixing the orders on  this horizon [D(-10) - > D2 ].Now when the planners are running the heuristics , they see that firmed orders are untouched but they see that there are some duplicate orders created.After analyzing i found  that there was no need to creating new planned orders.All the demands in future was covered as per lot per lot strategy and the demands in past were covered by the firmed orders.

I have tested the scenario in simulation version.Please suggest what I can do to avoid creating unneeded orders.

BR

Debasis Nanda

[marcelo_kayroquintaofigue · Accepted solution]

Hi Debasis.

I don`t know if a really understood your issue.

In your first screen... your ResOrders have Pegging to these Planned Orders?

When you ran your MRP, these planned order are in Past right?  Maybe instead run the MRP to create new planned orders, you can create a custom heuristic to move the existing ones to the new date.

Marcelo

[tiago_furlanetto]

Hi Debasis,

SAP_PP_002 uses Net Requirements Calculation method "Avoid Surpluses" - I assume you're using this one. In this case, Net Requirements Calculation follows logic below:

1. Demands which are in the past or within the Planning Time Fence consume receipts which are in the past or within the Planning Time Fence
   
   
2. Demands which are in the future consume receipts that can cover them on time
   
   
3. The remaining receipts (if any) consume the remaining demands even if they cannot be covered on time, starting from the latest demand to the earliest demand

Given this, if there are PP-Firmed planned orders in the future (after Current Date and Time + Planning Time Fence), these receipts will first be assigned to demands which can be covered on time. They will only be assigned to past demands if there is some quantity left in them when step 3 is reached.

As a result, the heuristic may create new receipts as early as possible in the horizon to cover the shortages from the past.

Options in this case are:

• Change Net Requirements Calculation method from "Avoid Surpluses" to "FIFO"
  
  
• Assign in the Product Master, Demand tab, Pegging subtab, an Alert Threshold for Lateness, as per KBA 2010195
  
  

          >> The Alert Threshold for Lateness from the Product Master only affects Net Requirements Calculation. It will not impact Reuse Mode "Delete unfixed Receipt Elements".

Regards,

Tiago

[former_member476084]

Hi All ,

Thank you all for the suggestion you have given to me.

@Marius talos - We cannot use that settings in the heuristics because the business wants the old planned should be deleted and new should be created and if they want to retain the order they will "date fix" it .

Let me tell you how system is behaving in my case.If you closely observe my screenshot no 3 , the orders which are generated again with same quantities has start date as 19:43.That was the exact system time when I ran the product heuristics.If you consider the order with 40 pieces which is firmed has end time as 19:53:27 and the new order created by heuristics has start time earlier than the end time of earlier one and hence the new orders are generated.Its the same case with other orders as well.

I am still confused why there is a need of creating a new orders because we already have one which is covering the old demands.

Issue rectified

We actually have different issue.Planners used to set the orders created by the heuristics prior to demands which is in past and fix it (Date Fix) so that heuristics cannot change the orders.But in our project we are daily running the "BOM Explosion" heuristics with retain operation date and modes.After testing I understood that this heuristics bring back all the past "Date Fix" planned orders to current date.The horizon we used earlier  for BOM explosion was from W0-W12.But to avoid facing this issue we change the time profile from D1-D84 . So now our BOM explosion was working from Today+1 day till D84.With this change all the firmed planned orders are now untouched in past.Currently we are able achieve the business requirement with this.

But still I could not understand the working of the standard heuristics and BOM explosion heuristics in my case

1. The main purpose of the heuristics is to avoid surpluses and created orders on the basis of lot for lot.System has done that but when we firmed the planned orders why system is creating duplicate orders.Why system is considering the dates when creating extra orders with same quantity.

2. What I understand about the explosion heuristics is that when we set the "Retain operation date" , it should not reschedule the orders .It works well on current day orders and the orders in future days but it is rescheduling all the past fixed orders to current date.

Thanks

Debasis Nanda

[Former Member]

Hello Debasis,

You have duplicate orders because you takes in consideration the past requirements but not the past receipts!

If you want to keep the fixed orders and delete the others unfixed, you can also try with Reuse Mode: Delete Unfixed Receipt and Explode Fixed Receipt Again

Thanks,

Regards, Marius

[Former Member]

Hello Debasis,

In the Basic Settings of the heuristic, please enter 10 days (or the numbers of days used in past) in the Maximum Earliness of a Receipt and Reuse mode - Use Suitable Receipts Elements.

Thanks,

Regards Marius 

[Former Member]

Hi Debasis,

See if this KBA 1502684 helps.

Thanks, Nikhil

[rupesh_brahmankar3]

Hello,

Which heuristic are you using?

Best Regards,

R.Brahmankar

[former_member476084]

Hi Rupesh ,

Thanks for quick response.

We are using copy of SAP_PP_002 and the only difference between the standard and our Z is the resuse mode we have used.We are using "Delete Unfixed receipts" in the reuse mode.So it will delete all the unfirmed planned orders and recreate new orders.

Thanks

Debasis Nanda

[Former Member]

Hi,

Please maintain the below values in Product master, Demand Tan, Pegging Tab

Maximum Earliness of Receipt:- 100000:00

Max. Lateness of a Receipt:- 100000:00

Run PPDS heuristic again.

Regards,

Anil

[former_member476084]

Hi Anil,

The values for max earliness and lateness are already maintained since we have demands in past.

Thanks

Debasis Nanda

[rupesh_brahmankar3]

Hello,

Please try by using Reuse mode = use suitable receipts with avoid surplus

Also refer KBA  2010195 - Avoid surplus receipts in PPDS planning by setting Alert Threshold in product master

Best Regards,

R.Brahmankar