SAP S/4HANA migration in purchasing: Effects of replacing MM-SRV with Item Hierarchies
With the migration to SAP S/4HANA, SAP plans to replace item type “D” (service item) in the SAP MM-SRV (Materials Management – Services) module. It will be replaced by the new Lean Services with Item Hierarchies. What initially appears to be a purely technical update has far-reaching implications for purchasing processes – especially for companies that actively use GAEB formats, item lists and item type D. This article highlights the changes associated with the switch to S/4HANA, the risks involved, and how companies can perform a thorough migration analysis.
Key Learnings
- With S/4HANA, SAP is replacing item type “D” (services) with Item Hierarchies – which will have significant consequences for the procurement of services and construction work.
- Many central functions of MM-SRV (GAEB compatibility, item types, supplement management, lots) are currently missing in the standard version of Item Hierarchies.
- For GAEB-compliant requests for quotation and item lists, one must check which sourcing tools can complement the missing SAP functionalities.
What will change in purchasing as a result of the changeover?
The switch from SAP ECC 6.0 to S/4HANA will result in few changes in purchasing – but one of them is crucial:
SAP plans to replace the item type "D" with Item Hierarchies. This new structure affects companies that:
- Procure services or construction work,
- Work with item lists,
- Issue GAEB-compliant requests for quotation,
- Use the SAP MM-SRV item type D.
What are the benefits of item type “D” in MM-SRV?
Item category D in the SAP MM-SRV module allows the structured mapping of service and construction projects. After a one-off system configuration, the company can:
- Map GAEB-compliant item lists
- Use titles and subtitles for item groups
- Use item categories such as alternative, eventual, or notice items
- Implement an effective supplement management system
As far as SAP is concerned, these functions will no longer be included in S/4HANA in the future. Instead, the new Item Hierarchies structure will be used for Lean Services.
What are item hierarchies in SAP S/4HANA?
Item Hierarchies in SAP S/4HANA represent a new data model for purchasing documents and item lists. They allow items to be displayed hierarchically, but they currently have significant functional limitations in their standard version:
| Function | Status in the item hierarchies |
| Several item types (e. g. alternative, notice items) | ❌ Not supported |
| GAEB-compliant structure | ❌ Not possible |
| Mapping of lots | ❌ Not provided |
| Traceability of changes | ❌ Not integrated |
Why is the change critical for purchasing?
Replacing MM-SRV in the future without a fully functional replacement in the form of Item Hierarchies would leave significant functional gaps in service procurement.
| MM-SRV (SAP ECC 6.0 / S/4HANA) | Item hierarchies (S/4HANA) |
| Differentiation of item types | ❌ Not possible |
| Transparent supplementary documentation | ❌ Not available |
| Structuring of lots | ❌ Not provided |
| GAEB data exchange with suppliers | ❌ Incompatible |
This creates critical process gaps, particularly inthe procurement of services and construction work.
What questions should companies ask when migrating?
In order to prepare for the migration to SAP S/4HANA in a structured manner, companies should analyze the following questions:
👉 How can existing MM-SRV documents and item lists be migrated?
👉 Which functions are available in the current Item Hierarchies version of SAP?
👉 Are there SAP Notes, OSS notes or customer enhancements that complement missing features?
👉 Is a third-party sourcing solution necessary in order to continue using GAEB-compliant structures, because even SAP Ariba does not support Item Hierarchies?
👉 Which purchasing processes need to be redesigned ?
How can one prepare for the S/4HANA migration?
Recommended preparatory steps for the migration to SAP S/4HANA:
- Gap analysis: Comparison of the ACTUAL functions in MM-SRV with the TARGET functions in Item Hierarchies
- Process analysis: Identification of affected processes in purchasing and controlling
- Evaluation of alternatives & workarounds: Use of third-party sourcing solutions
- Set up a test environment: Simulate real purchasing or construction projects with Item Hierarchies.
- Training & change management: Focus on technical project teams and purchasers
The good news
There is currently no official end-of-maintenance date for MM-SRV. Many SAP customers continue to use the module successfully with S/4HANA.
As long as Item Hierarchies are not fully functional and do not actually represent an alternative to MM-SRV, we do not recommend switching from MM-SRV to Item Hierarchies.
Conclusion
The replacement of MM-SRV by Item Hierarchies in SAP S/4HANA is not purely a technical change. It affects central procurement processes, project management, and requests for quotation.
Companies should actively prepare for migration, analyze functional gaps early on, and adapt processes accordingly. A structured approach ensures long-term success when introducing SAP S/4HANA in purchasing.
What is the difference between MM-SRV and Item Hierarchies?
MM-SRV is a tried-and-tested module for service items in SAP ECC 6.0 and S/4HANA. Item Hierarchies are the new model in S/4HANA and – if SAP has its way – will replace MM-SRV, albeit with considerably limited functions.
Can you process GAEB files with Item Hierarchies?
No. GAEB compatibility is not provided in the SAP standard. The use of third-party sorcing solutions is required.
Are Item Hierarchies a 1:1 replacement for MM-SRV?
No. Companies have to redesign processes and, if necessary, complement them with third-party providers.
Does SAP Ariba support Item Hierarchies in sourcing?
No, SAP Ariba is currently not compatible with Item Hierarchies.
Mapping item lists & GAEB in S/4HANA?
We show you how to efficiently implement structured requests for quotation and complex service items in SAP S/4HANA.
