MM / P2Padvanced

MM MRP Part 2: MRP Live (MD01N) — HANA-Optimized Planning and Scope

Key takeaway

Run MRP in S/4HANA with MRP Live: planning scope (plants, materials, product groups), performance on HANA, planning file and net change, what happens with materials not planned in HANA, logs and performance checks, and how MD01N replaces classic mass runs.

Explanation

📌 KEY POINTS
✅ MD01N (MRP Live) plans in the database layer on HANA for high performance.
✅ Scope: plants, materials, product groups, MRP controllers; net change based on the planning file or regenerative.
✅ Some planning scenarios are not processed in HANA and are planned with classic ABAP logic automatically (check logs).
✅ MD01N output lists planned materials, errors and performance data.
⚠️ Relying on old mass jobs (MD01/MDBT) in S/4HANA misses MRP Live benefits.

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▶ WHERE WE ARE
Part 1 explained MRP logic. Now S/4HANA execution.

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▶ 1. MD01N BASICS

Selection by plant, material, MRP controller, product group.
Processing: net change (planning file) vs regenerative.

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▶ 2. PLANNING FILE

Entries set by changes relevant to MRP; net change plans only flagged materials.

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▶ 3. HANA VS CLASSIC

Most logic runs in HANA; certain scenarios fall back to ABAP (per release).

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▶ 4. OUTPUT AND LOGS

Results, errors, performance; materials planned in ABAP marked.

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▶ 5. SCHEDULING

Background jobs per plant; frequency (daily, intraday).

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▶ STEP BY STEP

Run MD01N for a plant with net change.
Review the output and errors.
Check which materials were planned classically.

✅ CHECKPOINT: all relevant materials are planned nightly with no unexplained errors.

Code example

ABAP Code

===== STEP 1: MD01N =====Plant 1000 | scope: all materials with planning file entry (net change) | creation indicators (PRs/planned orders, schedule lines) ===== STEP 2: planning file =====Changes to stock, requirements, master data → planning file entry → planned in next net change run ===== STEP 3: monitoring =====MD01N output: planned materials, errors, runtime | logs for ABAP-planned materials

Real project scenario

A conversion project ran MD01N and found some materials were planned in classic mode and much slower. Logs showed special configurations causing fallback. Reviewing those settings and scheduling separate runs reduced total runtime while keeping results correct.

Common mistakes

Running regenerative every time.
Ignoring MD01N errors.
Not reviewing ABAP-planned materials.
Old job variants after conversion.
No runtime monitoring.

Best practices

Use net change daily.
Review output errors.
Analyse fallback materials.
Replace old jobs.
Track runtime.

Interview angle

Questions: "What is MRP Live?", "Net change vs regenerative?", "What is the planning file?"
Strong answer: MD01N on HANA, scope and planning file, net change, fallback to classic, output/logs, scheduling.

Practice this lesson

Quick check

1. Why does the MRP controller rely on the planning file (net change planning indicator) during a regular MRP run?

2. A planner runs MRP with the processing key 'NETCH' at plant level. What is the primary effect of this setting compared to 'NETPL'?

3. After conversion, MD01N shows some materials planned in classic mode. What should the team do?

Interview questions

1. Suppose you inherit an existing Material Requirements Planning solution. How would you review it before making a change?

Answer it in your own words first, then compare.

2. After moving to S/4HANA, the nightly MRP job takes too long and some materials behave differently. How do you optimize MRP Live?