Why does MRP change BOM of a rework production order with discontinued material?

[Dirk]

Dear Community, 

We created a rework production order to rework a material 150A to 150B. The material 150A that is to be reworked has a successor entry 150B in the master data, please see screen copy2.

Example: Rework order 6001880 in the screen copy 1

Task: Take material 150A quantity 3 and produce 3 times material 150B from it

Discontinuation date material 150A: 02.07.2025

Creation of the rework order: 15.10.2025

It looks like SAP has changed the material and quantities in the rework order to use up exisiting 150A (as desired) and the successor 150B (does not make any sense).

At time of the release of the rework order, there were enough parts 150A in free stock. We assume that the system has changed the quantities automatically, as the free stock has been reduced in the meantime.

Now we wonder if this is a MRP problem or wrong settings in the master data. We can't check for every MRP run to see if the system makes changes to rework orders when free stock situation changes.

Anyideas on this behaviour? What must be changed to avoid this?

I apologize the screen copies are in German language only.

Thank you.

Regards,

Dirk

[Andre_Depaula · Accepted solution]

In a manufacturing environment, when dealing with rework production orders in Material Requirements Planning (MRP), you might encounter situations where the Bill of Materials (BOM) changes, especially if there are discontinued materials involved. Here’s why MRP might prompt such changes and how this could happen:

Reasons for BOM Changes in Rework Orders

1. Material Substitution:

   • If a material in the original BOM has been discontinued, the system might automatically substitute it with an alternative material. This substitution is typically based on predefined configurations within the system to ensure that production can continue without disruption.

2. BOM Version Control:

   • BOMs often have multiple versions. When a material is discontinued, the system may switch to a different version of the BOM that aligns with available inventory and current production standards.

3. MRP Logic and Scheduling:

   • MRP is designed to optimize resource use and ensure production efficiency. If a required material is unavailable (e.g., due to discontinuation), MRP may adjust the BOM to reflect materials that are in stock or easier to procure, in order to prevent delays.

4. Rework Order Configuration:

   • For rework production orders specifically, the BOM might be adjusted to address the specific issues that led to the need for rework. This can include changes necessary to replace defective components or materials, some of which may be discontinued.

5. Integration with Change Management:

   • If your organization uses a change management process, discontinued materials might trigger a revision of the BOM automatically when MRP runs, depending on system settings or engineering change orders (ECOs).

Addressing BOM Changes Due to Discontinued Materials

1. Validate Material Availability:

   • Regularly review and update material masters and inventory records to ensure that MRP is operating with up-to-date information regarding material availability and status.

2. Configure Material Substitution Strategies:

   • Establish clear rules for material substitutions, including pre-approved alternative materials, to ensure they meet quality and production requirements.

3. Maintain BOM Version Records:

   • Keep meticulous records of BOM versions and changes, clearly documenting why and how changes are made so that production teams can understand the rationale and adhere to updated processes.

4. Regularly Update Production Orders:

   • Monitor and update rework production orders to reflect any changes in material status or availability. Ensure that these orders are aligned with the latest BOM versions.

5. Communicate with Procurement and Supply Chain Teams:

   • Work closely with procurement to ensure alternative materials are sourced proactively and align with production needs.

6. Review MRP Settings and Logic:

   • Periodically review your MRP settings to ensure it aligns with current business processes, and adjust parameters or logic to fit changing circumstances, like material discontinuations.

7. Implement Change Management Processes:

   • Utilize change management tools to handle updates to the BOM and material lists systematically, ensuring documentation and approval processes are followed.

[Dirk · Accepted solution]

Hi Andre, thank you for the quick reply and the comprehensive explanation.