Phase 11 — MRP / Consumption-Based Planning
🎯 In plain words
❓ Why it matters
MRP is a core exam area and the bridge between planning and purchasing: when MRP decides something is needed, it creates a purchase requisition automatically — which then becomes a PO. Understanding it shows you see the whole flow, not just manual data entry.
🧠 Key concepts you must know
1. MRP types — how the material gets planned
Set on the material master (MRP 1 view). The ones to know:
| Type | What it does |
|---|---|
| PD | Deterministic MRP — plans from actual demand (orders, reservations, forecasts). |
| VB | Manual reorder point — buy when stock falls below a level you set. |
| VM | Automatic reorder point — system calculates the reorder level for you. |
| V1 / V2 | Automatic reorder point with external requirements / plus forecast. |
PD = "plan to real demand." VB/VM/V1/V2 = "consumption-based" — react to stock dropping.
2. Lot-sizing — how much to order at once
The lot-sizing procedure turns "we need some" into "order exactly this much," e.g.:
- Lot-for-lot (EX) — order exactly what's needed.
- Fixed lot size — always order in fixed packs.
- Periodic — group a week's/month's needs into one order.
3. Safety stock
Safety stock is a buffer you keep to cover surprises (late delivery, demand spike). MRP treats it as untouchable, so it plans to stay above it.
4. The MRP run
- MD01 — total planning (whole plant).
- MD02 — single-level, one material (and its components).
- MD03 — single-item, one material only.
5. The stock/requirements list — MD04
The most-used MRP screen: a live picture of a material showing current stock plus everything coming in and going out over time (POs, PRs, orders, reservations), and what MRP proposes to fix shortages.
6. The planning file & how MRP buys
- Planning file — the list of materials flagged as "changed, needs replanning," so MRP only reprocesses what moved.
- Auto-PR: when MRP finds a shortage, it creates a purchase requisition for the right quantity and date.
- Source pick: MRP picks the vendor from the source list — the source flagged as relevant to MRP is the one it uses.
🛠️ Do it now — practise alongside
Don't just read — make SAP plan for you and watch a requisition appear out of nothing:
📘 MRP Deep Guide (full walkthrough) Scenario 14H — Source List + MRPThen set RM-IRON-01 to reorder-point planning, run MD03, and watch the auto-PR appear with the right vendor (from the source list). Open MD04 before and after to see the shortage get covered.
🔗 Connects to
- Phase 6 — Inventory Management: your stock figures are the input MRP plans against — wrong stock = wrong plan.
- Phase 3 — Master Data: the material MRP views (type, lot size, safety stock) and the source list drive everything here.
- Phase 4 — Purchasing: the auto-PR MRP creates is converted into a PO and sent to the vendor.
🎓 Cert focus & quick recall
C_TS452 Consumption-Based Planning area. Expect questions on MRP types, what MD04 shows, reorder-point logic, and how MRP sources.
PD vs VB MRP type — what's the difference?
PD plans deterministically from actual demand (sales orders, reservations, forecasts). VB is consumption-based manual reorder point — it ignores specific demand and simply triggers a buy when stock drops below the level you set.
What does MD04 show?
The stock/requirements list — a live, time-phased view of a material: current stock plus all receipts (POs, PRs, planned orders) and issues (orders, reservations), and MRP's proposals to cover shortages.
How does reorder-point planning work?
You (VB) or the system (VM) set a reorder level. When available stock falls below it, MRP proposes a procurement element (e.g. a PR) to bring stock back up — typically to cover up to the reorder point plus lot size.
How does MRP pick the vendor?
From the source list: the source marked as MRP-relevant is the one MRP assigns to the auto-created requisition.
✅ You're ready to move on when…
- You can explain PD vs VB and when you'd use consumption-based planning.
- You've run MD03 on a material and watched the auto-PR appear with the right vendor.
- You can read MD04 and explain what each line (receipt vs requirement) means.