Issue
This document evaluates the options for dealing with custom units of measure (ie non SAP / ISO Standard ones) and any customised conversions (eg from ISO to SAP) that have been created over time by Syensqo for use with Supplier and Customer integration, Ordering and Invoicing.
Using non standard UoMs / Conversions across the system will impact any internal integrations we have (eg between Ariba, TM and S/4 etc) as the UoMs have to be consistent across the entire landscape,. However retaining only standard Units of Measure could create difficulty engaging with suppliers and customers who do not use the same UoM standards as S/4 HANA.
Recommendation
It is recommended to use only the standard UoMs available within the S/4HANA system and other linked systems to ensure consistency ease of maintenance across the landscape.
Suppliers, customers, and any internal processes that require the use of non-standard UoMs should be reviewed and the custom UoMs replaced with standard UoMs - adhering to the ISO standard.
For legacy data using non standard UoMs these will have to be mapped and switched to standard UoMs at the point of data migration to ensure legacy data is compatible with the S/4 system.
Background & Context
In the past suppliers who did not send in a standard ISO or SAP Unit of Measure via a catalog, on an acknowledgement, or an invoice would get an error at the point of the data being entered (manually or by interface) on SAP.
This means that the transaction has to be checked and the Unit of Measure corrected by the supplier, causing delays. A fix for this issue is for the UoM to be added to the SAP UoM list as a custom unit to avoid recurrences. This has meant a gradually expanding list of custom UoMs.
The ERP Rebuild will mean a switch to SAP standard as a default. So a decision has to be made about how to handle these non standard UoMs that exist in WP1 and PF1.
- Stick only to the standard
- Copy over the non standard UoMs that are active
- Create a mapping tool to be map to suppliers custom UoMs, but do not permit any non standard UoM to be entered into SAP
Scale of Issue
The volume of POs and materials that use non standard UoMs is a small % of the total activity but not insignificant.
Volume of non-Standard (i.e. not in Standard S/4 HANA) UoMs in each system
| System | Non-Standard UoMs | POs in past 5 years | PO Items with non-Standard UoM | % | UoMs used in affected POs | Materials changed in 10 Years | Materials with Non-Standard UoM | % | UoMs used in Material Masters |
| QF2 | 404 | 4,642,346 | 184,587 | 4% | 66 | 613,651 | 27,648* | 5% | 32 |
| WQ2 | 357 | 2,877,450 | 82,007 | 3% | 73 | 567,413 | 5,995 | 1% | 51 |
Note - There are more Non-Standard UoMs used in POs than are used in Material Masters. This is means these UoMs are used in Text Based orders in the system
Most of these come from Punch-out Catalogs. These catalogs are maintained by the supplier and if they use a non Std UoM we cannot change that data ourselves but most large suppliers now adhere to the ISO standard.
Benchmark comparison
The project team have worked on other implementation projects where 700+ custom UoMs were successfully converted to ISO standards without any exceptions, so an approach to align to standard seems feasible.
Data from other standardisation projects shows that typically non-standard UoM usage occurs for one of 3 reasons:
- Using non-standard UoM because it was possible for users to conveniently create these, and use of standard UoMs was not enforced.
- Used for order of magnitude conversions (e.g. ppb vs ppm) - there is now better SAP functionality to handle this with standard UoMs
- Older legacy use cases which needed custom UoMs, but which now have standard functions available.
Assumptions
- The majority of suppliers and customers will be able to adhere to the SAP standard or ISO Units of Measure. This will require investigation.
- Non-standard UoMs can be converted to standard UoMs without exception. This appears feasible based on past experience and benchmarking data.
Constraints
- We wish to have SAP Standard only Units of measure within S/4 HANA to ensure that reporting and valuation is consistent and to simplify the maintenance of UoMs across the system
- We do not have total control what UoMs external suppliers use - some will use non standard UoMs
- We do not have total control over what UoMs suppliers send in via Punchout Catalogs and what customers send in via their Purchase Orders
Impacts
However, it is important to consider potential drawbacks or challenges associated with custom UoMs
- UoMs and mapping would have to be carried over from the legacy system either manually or by some custom extraction process.
- There is unlikely to be a standard SAP tool to do this copy over as the assumption with SAP is that the SAP and ISO UoMs are enough
- If custom UoMs are present in the system then they could be used by Syensqo staff when creating transactions and master data, rather than using them to map suppliers own UoMs to SAP standards. This could cause confusion downstream and so a review of how these are currently handled by the system should be carried out.
- If all suppliers are no longer using non-SAP or non ISO UoMs then this may not be a live issue. To decide which ones to carry over a review of UoMs currently received on invoices would need to be be carried out.
- Accepting nonstandard UoMs without proper and complete mapping can cause confusion in standard reports, blocking global analysis.
- There may be legacy data to be transferred that uses these custom UoMs
- UoM mismatches can occur in other streams – eg O2C where customers send in non standard UoMs causing similar issues to procurement.
- If we create custom UoMs they will need to be maintained and validated across the entire system landscape to prevent any interfacing issues.
- The volume of activity not using std UoMs is significant - sticking to Std only could cause disruption
Business Rules
For the purposes of standardisation, only the Standard SAP / ISO Units of Measure should be permitted within the SAP. But this does not preclude mapping non Standard UoMs to Standard ones at the point of integration.
Options considered
It would be painful to go through the same UoM errors that Syensqo has already solved by adding in custom UoMs.
However allowing non standard UoMs creates additional complexity and would need to be analysed across the system in order to see how big an issue it is and any downstream or reporting impacts.
Option 1: Use only SAP / ISO Standard UoMs and conversions, do not copy over any custom entries
The organisation uses only the standard SAP offering for SAP and ISO UoMs and conversions.
Advantages:
- No need to ensure that UoMs are correctly replicated across the landscape
- Reduces the long-term maintenance burden as there are fewer custom elements to manage.
- No effort required to develop a process to transfer the UoMs
- No issue with non-standard UoMs impacting reports
- No potential confusion due to unexpected downstream use of non-standard UoMs
- Ensures that only standardized data is used in the new system, which can simplify future upgrades and integrations.
Disadvantages:
- May hit the same issues that have already been solved when receiving transactions from suppliers & customers
- May invalidate legacy data that uses custom UoMs – e.g. Supplier Invoices, POs and Customer Invoices/Sales Orders etc that would need to be altered
- If plan is only to use SAP standards, then another way of correcting the suppliers/customers who send in non-standard UoMs need to be used
Option 2: Carry over any active custom UoMs/conversions from As-Is
Take over the current custom UoMs as they are, including any mapping
Advantages:
- UoM Problems that are already solved / mapped do not re-occur
- No issue with legacy data that use custom UoMs (if any)
- No impact on suppliers/customers that submit non standard UoMs
Disadvantages:
- Need to replicate custom UoMs across landscape
- Maintenance burden as custom UoMs will need to be supported and .
- Any pre-existing issues (e.g. in reports due to unexpected UoMs) will also re-occur (if we dont correct the data)
- May have an impact on other standard tools or integrations
- Need to develop a process to transfer UoMs
- Risk of conflicts with standard UoMs and future upgrades or integrations with other systems.
- Potential confusion due to unexpected downstream use of non-standard UoMs
- Need to review data to see which UoMs are actually in use to avoid taking over defunct ones
Evaluation
Based on the evaluation of the solution options, it is recommended that the "Use only SAP Standard" approach is used as a starting position.
This follows the Simplification/Standardisation approach of the project and minimises any maintenance burden going forward.
We can react to any UoM exceptions that cannot be switched to Standard SAP/ISO UoMs and possibly support them by mapping to a S/4 Standard at the point of integration. This would let the system accommodate non standard UoMs from suppliers or customers but only have Standard UoMs within the S/4 System. This would be achieved using enhancements and on an exception basis.
Impact on 3rd Parties
Suppliers and Customers should not be using non standard ISO Codes going forward and should be pushed to do so
Impact on Legacy Data
Need to see how many custom UoMs are used in the legacy data and take action (remap etc) where needed.
| Criteria | Option 1: Use only SAP Standard UoMs, do not copy over any custom UoMs | Option 2: Carry over any active custom UoMs from As Is |
|---|---|---|
| Adhere to SAP Std UoMs on reports, data etc |
|
|
| Impact on suppliers/Customers |
|  Suppliers/customers don't have to change |
| Impact on data migration |
| no mapping required |
| Requires enhancement |
| no enhancement required |
| No recreating errors already solved in ECC |
| no impact |
| Maintain UoMs across landscape |
|  Custom UoMs need to be maintained |
See also
Insert links and references to other documents which are relevant when trying to understand this decision and its implications. Other decisions are often impacted, so it's good to list them here with links. Attachments are also possible but dangerous as they are static documents and not updated by their authors.
