- SAP Managed Tags
In the world of manufacturing, precision is paramount. The accuracy of material consumption plays a significant role in ensuring smooth operations, especially when using systems like SAP ERP and SAP Digital Manufacturing (SAP DM). A critical challenge arises when discrepancies occur due to differing decimal precision levels between these two systems, potentially leading to overconsumption of materials. In this blog, we’ll explore a common issue related to Bill of Materials (BOM) component quantities in SAP ERP and SAP Digital Manufacturing and discuss an effective solution to address this problem.
The Problem: BOM Quantity Rounding Discrepancies
When managing production orders or process orders in SAP ERP, the system operates with BOM component quantities defined at the order level, maintaining precision up to three decimal places. On the other hand, SAP Digital Manufacturing calculates and stores BOM component quantities for individual SFC units, and it can store up to six decimal places for each component.
This difference in precision between the two systems becomes problematic when SAP Digital Manufacturing calculates the BOM component for each SFC. After rounding to six decimals, a slight overestimation can occur when this value is multiplied back to the order level in SAP ERP, which only supports up to three decimal places.
Let’s look at an example:
- ERP Order Quantity: 9
- BOM Component (grams): 25
For each SFC in SAP Digital Manufacturing, the component is divided: 25 / 9 = 2.777778 (rounding to six decimal places) when the order is downloaded and imported into SAP Digital Manufacturing.
However, SAP Digital Manufacturing maintains this value as 2.777778, rounded to six decimals. When SAP Digital Manufacturing reports the total back to SAP ERP (which uses only three decimals), it results in: 2.778 * 9 = 25.002
This results in a slightly higher BOM component quantity (25.002 instead of 25 grams), leading to overconsumption, which SAP Digital Manufacturing (and SAP ERP) then detects and blocks the transaction to prevent overconsumption, causing disruptions in production.
The Solution: Aligning BOM Precision Across SAP ERP and SAP Digital Manufacturing
To address this issue, we can expose the BOM component calculation during the production order and process order download, making the process more transparent and manageable. The solution involves leveraging the XSLT to handle the BOM component calculation at the desired level of precision.
- Exposing the BOM Calculation:
By exposing the calculation logic in the production order download and process order process, similar to previous versions (V1 Order Download), we can ensure that both SAP Digital Manufacturing and ERP are aligned in terms of how quantities are calculated and managed. The Production Order LOIPRO05 V2 Download and Process Order LOIPRO05 V2 Download XSLT has the following segment commented which can be used to map the BOM Component Qty calculation according to customer requirements.
<QuantityInBaseUnit>
<xsl:value-of select="format-number((BDMNG div ../../../GAMNG) , '0.######')"/>
</QuantityInBaseUnit>
- XSLT Calculation with Precision Control:
In the XSLT integration layer (Workflow configuration), we can use the following logic to restrict the BOM component to three decimal places when calculating for SAP Digital Manufacturing.
For instance:
<xsl:value-of select="concat(substring-before(format-number((BDMNG div ../../../GAMNG), '0.0001'), '.'), '.', substring(substring-after(format-number((BDMNG div ../../../GAMNG), '0.0001'), '.'), 1, 3))" />
The above XSLT segment will floor the value to 3 decimal (2.777). This ensures the SAP Digital Manufacturing system stores the BOM component as 2.777000 in its database for the above-mentioned scenario, maintaining six decimals but with the value matching ERP's three-decimal format.
- Managing the Small Differences:
Even though flooring the BOM Component quantity to 3 decimal value addresses the problem in SAP Digital Manufacturing, there is a small discrepancy with the components consumed in SAP Digital Manufacturing and reported to SAP ERP. After multiplying 2.777 by 9, the result posted is 24.993 grams— slightly less than the required 25 grams. To handle this small shortfall, the customer can design a Production Process Design (PPD) to consume the remaining 0.007 grams (as a non-BOM component) at the completion of the last SFC or at any stage of the shop floor operation of this last SFC. This ensures that any rounding differences are absorbed appropriately without causing material overconsumption.
- In order to find the difference in quantity, we can maintain the Order BOM component Quantity as a custom field in BOM Component (e.g. Custom field defined as “Order Qty”). This can be done when the order is downloaded by mapping the order quantity to this BOM Component custom field ‘Order Qty’ for each component.
- Design a Production Process Design (PPD) which can be triggered on the last SFC completion at a particular step, either manually or automatically, by checking if the current SFC is the last SFC being processed and then find all the components assembled on order level and compare it with custom field value for “Order Qty” maintained on BOM Component level.
- If there are any difference in Quantity to be consumed, use assemble component API to consume this difference in quantity as non-BOM component by setting the flag “isBomComponentAssembly” to false in the API payload.
The steps outlined above provide one example of how to manage small differences in quantity. However, customers can develop their own logic to address this issue based on their specific needs.
Why This Solution Works
The key benefit of this approach is that it strikes a balance between SAP ERP’s precision limitations and SAP Digital Manufacturing’s requirements for detailed shop floor activities. By integrating XSLT transformations and leveraging custom fields to manage BOM component quantities, we maintain the accuracy of material consumption while ensuring that small discrepancies are managed effectively during production. The idea is to reduce the BOM Component consumption in SAP Digital Manufacturing to the closest accurate amount, which can be distributed across all SFC equally, report the reduced quantity to ERP, and handle the small discrepancy in a separate step.
Additionally, this method ensures that all BOM components are distributed as accurately as possible across production orders and SFCs, minimizing the impact of rounding errors on manufacturing efficiency.
Conclusion
Material management is a critical aspect of modern manufacturing, and even small errors in calculation can have significant downstream effects. By addressing the precision differences between SAP ERP and SAP Digital Manufacturing, this solution ensures that BOM components are managed accurately and efficiently, helping prevent overconsumption and maintaining smooth production workflows.
With the use of XSLT for enhanced precision control, and strategies like utilizing a PPD for handling small discrepancies, manufacturers can confidently manage their BOM components without being concerned with the challenges caused by decimal precision limitations.
If you’re facing similar issues in your production environment, this approach can be customized and implemented to suit your specific needs. It is another step toward optimizing your SAP systems for greater accuracy and efficiency in manufacturing operations.
Note: This above blog is only applicable for SAP ECC and SAP S4Hana, not for S4HC.
| User | Count |
|---|---|
| 9 | |
| 2 | |
| 2 | |
| 2 | |
| 1 | |
| 1 | |
| 1 | |
| 1 | |
| 1 | |
| 1 |
