# SAP MD01N (MRP Live) vs MD01: How to Run MRP Correctly > Source: https://netray.co/erp-help/sap-md01n-mrp-live-vs-md01-how-to > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: ERP Help ## Short answer MD01N is MRP Live: the same planning logic as classic MD01, but executed inside the SAP HANA database instead of looping through materials in ABAP. Run it from MD01N by entering the plant, choosing a processing key (net change or regeneration), setting the purchase requisition and scheduling parameters, and executing in the background for large scopes. ## Kind how-to ## System sap ## Erp SAP S/4HANA and ECC on HANA ## Module PP / Material Requirements Planning ## Query SAP MD01N MRP Live vs MD01 difference how to run ## Alternate Queries - MD01N MRP Live how to run planning - MD01 not available in S/4HANA use MD01N - MRP Live vs classic MRP SAP - MD01N planning mode regenerate net change ## Applies To SAP S/4HANA (all releases) and SAP ECC 6.0 EHP7 or later running on SAP HANA. Classic MD01 remains on non-HANA ECC systems. ## Steps ### How to run MRP Live with MD01N **Items:** Open transaction MD01N (Logistics > Production > MRP > Planning > Total Planning > Online / Background, MRP Live). Enter the Plant, or an MRP Area if MRP areas are in use. Optionally restrict the run with a material, MRP controller, or product group selection under the Planning Scope. Pick the Processing Key: NETCH for net change in the whole planning horizon, NETPL for net change in the planning horizon, or NEUPL for regenerative planning of all materials. Set Create Purchase Requisitions (opening period or all), Delivery Schedules, and Create MRP List according to your process. Leave MRP list creation off for very large runs if planners use MD04 only. Set the Planning Mode (adapt planning data, or delete and recreate planning data) and the Scheduling indicator (basic dates, or lead time scheduling and capacity planning). Choose Execute for a small scope, or schedule as a background job through the menu for the full plant. Check the log that MD01N shows on completion. Review results in MD04 (stock/requirements list) and MD07 (collective display) and compare exception messages with MD05 if lists were created. If results differ from what classic MD01 gave you, check the planning file entries (MDVM) and the materials flagged with the net change indicator before blaming the logic. ## Sections ### What actually changes between MD01 and MD01N **Body:** Classic MD01 reads each material from the planning file, runs the MRP logic in the ABAP application server, and writes planned orders and requisitions back one material at a time. MD01N pushes the heavy lifting to the HANA database through procedures, so the same BOM explosion, netting and lot sizing happens close to the data. The business rules (planning strategy, lot-sizing procedure, safety stock, planned delivery time, MRP type) are the same material master fields you already maintain on the MRP 1 to MRP 4 views. The practical differences are in how you run and tune it. You do not size parallel processing sessions the way you did with MD01 and parallel processing profiles; the database parallelises the work. Run times for a full regeneration that took hours in ABAP often drop sharply, but that is a mechanism rather than a promise, and it depends on data volume, number of BOM levels and how many materials actually changed. ### Net change, net change in horizon, and regeneration **Body:** NETCH plans only materials that carry a net change flag in the planning file, set when a goods movement, a sales order change, a BOM change, or a master data change affects planning. NETPL does the same but limits the check to receipts and requirements within the planning horizon defined in the planning time fence or the plant parameters. NEUPL plans every MRP-relevant material regardless of flags and is the right choice after bulk master data changes, a go-live, or when you suspect the planning file is corrupt. A good operational pattern is a nightly net change run for the plant and a weekly or monthly regeneration outside working hours. If you run NEUPL for the whole plant during business hours you will lock materials that users need for goods movements and order confirmations, and you may see lock messages that look like application errors but are simply the planning run holding the material. ### What does not behave the same: custom logic and enhancements **Body:** The most common surprise after a move to MD01N is that a custom enhancement no longer fires. Classic MRP had user exits and BAdIs executed in ABAP at known points. In MRP Live the core calculation does not run in ABAP, so enhancements written for the classic program may not be called, or have been replaced by newer BAdIs provided for the HANA version. Check the SAP Notes for your release for the list of supported BAdIs and the functions MRP Live does not cover. Before you assume a bug, compare a small set of materials. Run MD02 (single-item, multi-level) in classic mode where it is still available, run MD01N for the same plant and material, and compare the planned order quantities and dates in MD04. If they differ, the cause is usually a custom exit, a different scheduling setting, or a stale planning file entry rather than a defect in the new logic. **Code:** SELECT matnr, werks, plifz, webaz, dismm, disls FROM marc WHERE werks = '1000' AND dismm <> 'ND' -- use SE16N on MARC to review MRP type (DISMM) and lot size (DISLS) before comparing runs ### Scheduling the run and reading the log **Body:** For production, schedule MD01N through SM36 or the Application Job template so it runs after the nightly goods movement and billing jobs, not before them. Planning before the last confirmations post means planned orders are created against stale stock. Keep a separate variant for each plant or MRP controller group if different groups need different planning times. The result log shows the number of materials planned and any materials that failed, usually because of a missing production version, a missing routing, or a locked material. Treat the failed list as a work queue. A material that fails repeatedly is a data problem in the material master or BOM, not a planning problem, and it will keep producing wrong or missing supply until fixed. ## Pitfalls - Running NEUPL for a whole plant in working hours locks materials and blocks goods movements and confirmations. - Assuming classic user exits still run. Re-test every MRP enhancement after moving to MD01N and check SAP Notes for supported BAdIs. - Scheduling MRP before the night's last confirmations and goods issues, so planned orders are built on stale stock. - Ignoring the failed-materials list in the log. Missing production versions and BOMs silently remove supply from planning. - Comparing MD01N results to old MD01 results without aligning the scheduling indicator and planning mode first. ## Ai Angle An AI assistant grounded in your SAP system (ERPray, read-only by default) can answer the question planners actually ask after a run: why did material X get this planned order? It reads MARC, MDKP, MDTB and the MD04 data, shows the query it used, and explains which requirement, safety stock or lot-size rule created the receipt. It does not replace MD01N or change planning parameters, and any write-back would need a human approval step. ## Faq ### Is MD01N the same as MD01 with a new screen? **Answer:** No. The planning logic and master data fields are the same, but MD01N runs the calculation in the HANA database through procedures instead of in the ABAP application server. The selection screen differs, parallel processing profiles are not used the same way, and custom ABAP exits written for classic MRP may not execute. ### Can I still use MD01 in S/4HANA? **Answer:** In S/4HANA, MD01N is the supported total planning transaction and classic MD01 is obsolete for new processes. Check the simplification list for your release. Single-item planning transactions such as MD02 and MD03 remain available for planners who need to replan one material. ### Which processing key should I use daily? **Answer:** Use NETCH or NETPL for the regular nightly run so only changed materials are planned. Use NEUPL for a regeneration after bulk master data changes, a migration, or when you suspect the planning file entries are inconsistent. Schedule NEUPL outside working hours because it plans every MRP-relevant material. ### Why did MD01N skip a material? **Answer:** Common reasons: the MRP type is ND, no net change flag was set for NETCH, the material is locked by another user, or it has no valid production version or BOM. The job log lists failed materials. Check MARC for the MRP type, then MD04 and the log for the specific message. ## Search terms MD01N, MRP Live, MD01 vs MD01N, SAP MRP Live HANA, MD01N processing key NETCH NEUPL, SAP net change planning, MD01N BAdI, SAP S/4HANA MRP run, MRP Live planning mode, MD01N background job --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json