What it is
MRP Live (transaction MD01N) is S/4HANA's material requirements planning run that executes in-memory on SAP HANA. Instead of pulling data up into the application server and looping through it, much of the planning logic runs where the data already lives — so it's dramatically faster than classic MRP (MD01).
Why it changes the game
- Speed — planning that took a long overnight window can run in a fraction of the time.
- Frequency — fast enough to run more often, even intraday, so the supply plan reflects reality instead of last night's snapshot.
- Scope — plan by material, plant, or MRP scope (e.g. only what changed), not just a big-bang full run.
What actually happens in a run
The planner then works the results in the Fiori apps — Monitor Material Coverage (where are the shortages?) and Manage Material Coverage (fix them) — rather than trawling MD04 alone.
One honest nuance
Not every classic feature runs in-memory. Where a material uses logic MRP Live doesn't yet support, SAP automatically routes that material to classic MRP in the same run — so results stay complete.
Worth knowing, not worth fearing. A planner who understands "routed to classic" won't panic when a subset of materials behaves differently.
Why it matters for training
A planner who only knows classic MD01 will run MRP Live and then… go back to old habits in MD04. The one taught the Fiori coverage apps and what "routed to classic" means actually gets the speed and the better daily workflow.
New engine, new muscle memory — that's a training job, not a memo. It lands from role-based training built on your configured process, before go-live.