Lesson 3 of 6
Restrictions
10 min
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MRP Live does not support every function classic MRP supports. When a material needs something MRP Live cannot do, the system plans that material with classic MRP in the same run. SAP Learning describes the mechanism: each low-level code is first planned with MRP Live, then the materials it could not plan, or that hit errors, are planned with classic MRP. For the planner the run still looks like one run. For a tester and an architect, it matters which engine planned what.
- Low-level code 0MRP Live plans all supported materials in SAP HANA
- FallbackUnsupported or failed materials of code 0 planned by classic MRP
- Low-level code 1MRP Live again for the next level, then fallback
- …Repeated down to the lowest code
- Run logShows materials planned and any that switched engines or failed
Where the restrictions are documented
SAP maintains the list of restrictions in SAP Note 1914010 (MRP Live restrictions). The list depends on release and support package and has shrunk as MRP Live gained functions, so read the version that matches your system rather than a blog post or an old course. SAP Learning names two examples that are useful anchors: some lot-sizing procedures such as optimum lot sizing are not supported, and forecast-based planning (MRP type VV) is not supported.
| Category | Example to look for in SAP Note 1914010 | What it means for Contoso |
|---|---|---|
| Lot sizing | Optimizing lot-sizing procedures | Check all lot-size keys in use in plants 1710 and 1720 |
| MRP types | Forecast-based planning (VV) | Service parts planned with VV will run in classic MRP |
| Enhancements | Classic ABAP user exits and BAdIs are not executed inside SAP HANA; MRP Live offers its own AMDP-based BAdIs for some extensions | Kenji lists ECC MRP enhancements and decides: retire, redesign, or force classic |
| Special functions | Functions listed for your release (check the note) | Map each to the materials that use it |
How to work through the restrictions. The examples in the first two rows come from SAP Learning; always verify against the note for your release.
Finding the affected materials
Do not guess which materials fall back. SAP provides tools to check which materials MRP Live cannot plan and why, and a way to force selected materials to classic MRP on purpose (for example, transaction MD_MRP_FORCE_CLASSIC). The exact tools and their names depend on your release; the SAP notes referenced from 1914010 list them. Run the check after each mock conversion and keep the output as evidence.
- Does the material use a function in SAP Note 1914010?Yes → it will be planned by classic MRP · No → MRP Live
- Is the function still needed after conversion?Yes → accept classic MRP for it and test both engines · No → change master data to a supported setting
- Does custom ECC MRP logic apply to it?Yes → redesign, or force classic deliberately and document why · No → continue
- Is performance acceptable for the classic share?Yes → sign off · No → reduce the classic share or reschedule runs
Why this matters in a conversion
In ECC, Contoso planned with classic MRP and a handful of enhancements written over fifteen years. After the conversion, those enhancements do not run for materials planned by MRP Live, because MRP Live does not execute ABAP logic during the database procedure. That can quietly change results: a custom rule that rounded rotor requisitions to pallet quantities simply stops. SAP S/4HANA offers AMDP BAdIs (database procedures) as extension points for MRP Live, so some rules can be re-implemented there; others are better replaced by standard settings such as a rounding profile. The safest approach is to treat every MRP enhancement as a design decision with an explicit test.
What would you do?
After mock conversion 1, rotor requisitions are no longer rounded to pallets of 250 as they were in ECC. No configuration was changed. What is the most likely cause?
| Contoso enhancement in EP1 | Decision | Test |
|---|---|---|
| Pallet rounding for CMC-RTR-200 (250 per pallet) | Replaced by rounding value 250 in the MRP 1 view | Requisitions in multiples of 250 in CMQ |
| Exclusion of obsolete materials from the run | Replaced by MRP type ND on the material | Material absent from the run log |
| Custom safety stock for peak months | Re-implemented as AMDP BAdI by Kenji's team | Peak-month proposals equal EP1 for 10 materials |
| Special logic for two service parts on VV | Kept on classic MRP deliberately | Run log shows both in the classic share |
Illustrative course data: how Contoso disposed of its four ECC MRP enhancements.
- Materials MRP Live cannot plan are planned by classic MRP in the same run, level by level.
- SAP Note 1914010 lists the restrictions for each release; examples include optimum lot sizing and MRP type VV.
- Custom ABAP logic in classic MRP is not executed by MRP Live.
- Use SAP's check tools to list affected materials; force classic only on purpose and document why.
Check your understanding · not graded
Lesson check
1. What happens to a material that MRP Live cannot plan?
2. Which SAP Note documents MRP Live restrictions?
3. Which MRP type does SAP Learning name as not supported by MRP Live?
4. Why do custom ECC MRP enhancements stop working for many materials?