Scenario 26 — MM ↔ PS Integration (Project-Based Procurement / WBS)
📊 Business Case
This scenario is where MM hands off to Project System (PS) for capital projects. A big capex job — building a new plant extension — is structured in PS as a Work Breakdown Structure (WBS): a tree of project phases. Every purchase (steel, equipment, concrete) is tagged to a specific WBS element with account assignment P (Project), so the cost rolls up to the project instead of hitting a cost center or inventory. At completion, the accumulated cost settles through an Asset Under Construction (AuC) to the final fixed asset. It shows MM enabling long-running capex across the SAP suite.
🕐 When to use it
For any project-based or capex procurement — plant builds, expansions, large installations — where cost must be tracked per project phase and ultimately capitalized as an asset.
❓ Why it matters
It teaches account assignment P and WBS-based cost accumulation — different from a cost center. The project (not stock) carries the cost, enabling accurate capex tracking and the AuC → final-asset chain.
👤 Who triggers it
The PS consultant builds the project/WBS; the MM buyer raises POs tagged to a WBS element and handles GR/IV; PS/CO settles the WBS to AuC (CJ88) and on to the final asset.
🔁 The key distinction
Cost rolls up to the project, not inventory. With account assignment P the spend lands on the WBS element and is visible in the project cost report, then capitalizes via AuC — never sits as stock.
💰 Financial Impact — The Easy-Money Example
PakSteel buys 100 TO of structural steel beams (PKR 80,000/TO = PKR 8,000,000) for the galvanizing plant build. The PO carries account assignment P against WBS element GALV-001-CONST, so the money rolls up the project tree toward a fixed asset — never into inventory:
The big idea: account assignment P means project spend is never inventory — it is charged to the WBS element at GR and rolls up the project. CJ88 then settles the WBS to an Asset Under Construction, and at go-live the AuC becomes the final depreciating asset. The project, not stock, holds the capex until it is capitalized.
🇵🇰 The Business Story
🎯 What you'll learn
- Account assignment
P(Project / WBS) on the PO line - WBS-based cost accumulation (different from cost center)
- Asset Under Construction (AuC) handling for capex projects
- Multi-step settlement: WBS → AuC → Final Asset
- How MM enables long-running capex projects in SAP
⚙️ Prerequisite Setup
- Skip this scenario (PS is specialized — many companies don't use it)
- Substitute with Scenario 6 (Asset Procurement direct, account assignment A) — simpler, similar MM mechanics
- OR work with a PS consultant to create a basic project + WBS for testing
Goods Receipt · Reference Purchase Order → mvt 101 (the account-assigned P PO — cost goes to the WBS element, not stock). Full guide: MIGO Selection Bar.
🔧 Step-by-Step — Transaction Flow
26.1 — PS Project + WBS · CJ20N
PS consultant creates the project structure (typically before MM gets involved):
- CJ20N · Project Definition: GALVAN-PRJ-001 "Galvanizing Plant Extension"
- WBS elements (project breakdown):
- GALV-001-CONST: Construction phase
- GALV-001-EQUIP: Equipment phase
- GALV-001-INST: Installation phase
- Each WBS has cost element, account assignment, settlement rule (to AuC asset)
- Save and release the project
26.2 — Create PO with WBS Account Assignment · ME21N with acct P
- ME21N · Vendor: Pak Steel Structures (or any vendor)
- Line: Material "Structural Steel Beam I-200" · Qty 100 TO · Net Price 80,000 PKR/TO
- Account Assignment Category:
P(Project) - Account Assignment tab → WBS Element: GALV-001-CONST
- G/L auto-determined for project consumables
- Save → PO #
Result: When GR happens, cost goes to WBS GALV-001-CONST, not a cost center.
26.3 — GR + MIRO — Standard, but cost tags to WBS
Same as regular P2P, just the cost accumulates on the WBS element.
| Project Construction Expense (4500xx) | Dr 8,000,000 | WBS: GALV-001-CONST |
| GR/IR (191100) | Cr 8,000,000 | — |
26.4 — Settle WBS → Asset Under Construction (AuC) · CJ88
Periodically (monthly during project), PS/CO consultant settles WBS cost to AuC.
At project completion, AuC settles to final operational asset via AIBU.
- Configure your PO doc types to ALLOW account assignment P
- Create custom PO doc type for capex projects (ZCAP) — see Scenario 20
- Ensure release strategy triggers Director/Board approval for PS-tagged POs
- Coordinate with the PS team on planned vs actual procurement timelines
- Handle change orders to project-specific contracts
✅ Verification
| # | T-code | Check |
|---|---|---|
| 1 | CJ20N / CN41 | Project GALVAN-PRJ-001 released with WBS elements GALV-001-CONST/EQUIP/INST |
| 2 | ME23N | PO line has Account Assignment Category P with WBS Element GALV-001-CONST |
| 3 | FB03 / MB03 | GR document: Project Construction Expense (4500xx) Dr / GR-IR Cr — no inventory (300xxx) line |
| 4 | S_ALR_87013542 / CJI3 | WBS GALV-001-CONST shows the 8,000,000 actual cost in the project cost report |
| 5 | AW01N | After CJ88, the Asset Under Construction carries the settled project cost |
🎓 Interview-Ready Answers
Q: What does account assignment category P mean, and how is it different from a cost center?
P = project — the procured item is charged to a WBS element rather than received into stock or charged to a cost center. At GR there is no inventory posting; the cost lands on the WBS and rolls up the project tree. A cost center (account assignment K) collects period/department cost; a WBS collects project cost across phases and ultimately capitalizes it as an asset.
Q: Walk me through how project procurement cost becomes a fixed asset.
POs tagged to WBS elements post their GR cost to those WBS elements (e.g. 4500xx Dr / GR-IR Cr). The WBS accumulates all project spend. Periodically CJ88 settles the WBS to an Asset Under Construction (AuC). At project completion the AuC is settled to the final operational asset (via AIBU), which then depreciates. So the chain is WBS → AuC → Final Asset.
Q: What is a WBS element and why structure a project that way?
A Work Breakdown Structure decomposes a project into hierarchical elements (phases like Construction, Equipment, Installation). Each WBS element is a cost collector with its own budget, account assignment and settlement rule. Tagging each PO to the right WBS gives phase-level cost visibility, budget control, and clean settlement to AuC — far better than dumping all capex on one cost center.
Q: What is the MM consultant responsible for in this PS scenario?
Not PS config. MM ensures the PO document types allow account assignment P, often creates a dedicated capex PO doc type (ZCAP), sets the release strategy so project POs route to Director/Board approval, coordinates planned-vs-actual procurement timing with PS, and handles GR/IV and change orders for project contracts. MM enables the buy; PS, CO and Asset Accounting own the capitalization.