sap-wm

name: sap-wm description: > This skill handles SAP WM (Warehouse Management — ECC legacy module) including Warehouse Structure (LS01N/LS02N), Storage Type/Section/Bin (LS01/LS03N), Transfer Order (LT01/LT03/LT0E), Transfer Requirement (LB01/LB10), Picking/Putaway Strategies, WM-MM/SD Integration, Physical Inventory (LI01N/LI02N), and Decentralized WM (MWMII). Also covers ECC WM → S/4HANA migration (WM deprecated in S/4HANA; use EWM instead). Use when user mentions WM, 창고관리, warehouse, storage bin, 저장위치, transfer order, 이관오더, putaway, 입고적치, picking, 피킹, storage type, 저장유형, quant, decentralized WM, LS01N, LS03N, LT01, LB01, LI01N, MWMII. allowed-tools: Read, Grep

1. Environment Intake (Critical)

ECC vs S/4HANA Alert: WM is DEPRECATED in S/4HANA (all releases).

• S/4HANA on-premise / RISE: Use embedded EWM (sap-ewm skill) or Stock Room Management
• ECC 6.0: WM fully supported through extended maintenance (2025)
• Dual-run transition: ECC WM → S/4HANA EWM requires process redesign (not 1:1 mapping)

Questions to ask user:

1. ECC 6.0 (which EhP?) or S/4HANA already?
2. Warehouse network: single, multi, or 3PL outsourced?
3. RF terminal / barcode capability active?
4. Current issue: process bottleneck, data accuracy, integration, or migration planning?

2. Warehouse Structure (LS01N / LS03N / LQUA)

Hierarchy & Tables

Warehouse Master (LAGP) Key Fields

• LGNUM: Warehouse number (2 chars, e.g., "01")
• LGSYS: Flag — W (WM system) or D (Decentralized)
• WERKS: Plant assignment
• LGPLA format: 3-digit ST + 3-digit section + 3-digit bin (e.g., "001001001")

Issue: "Cannot create storage bins"

Root Cause: Missing storage section linking Check: SE16N → LEIN (verify section exists); SE16N → LQUA (verify bins) Fix: LS03N → Create Section → Create Bins (batch entry) → Trigger MRP

3. Transfer Order (LT01 / LT03 / LT0E / LT06)

Key T-codes

Process Flow

GR (MIGO 101) → TR created → LB10 batch → TO created (LT01)
  ↓
Release (LT03/LT0E) → RF Execute (LT0G) → Confirm (LT0A)
  ↓
Stock in LQUA, available for picking

Tables (LTAK / LTAP)

LTAK (header):

• LGNUM, TANUM (TO number)
• TPTYP (10=picking, 20=putaway, 30=inventory)
• KZVLP (two-phase picking flag)

LTAP (lines):

• LGPLA (source bin), LGPLB (dest bin)
• MATKX (material), MENGE (qty), ERFME (UOM)
• LGMNG (actually moved qty)

Issue: "Transfer Order stuck in Pick phase"

Root Cause: Partial RF execution + system failure Check: SE16N → LTAP: LGMNG vs MENGE; LT01 → Messages tab Fix: LT0A (resume confirm) OR LT04 (cancel & recreate)

4. Transfer Requirement (LB01 / LB10)

Auto-Creation Triggers

Key Transactions

LB10 Batch Job (Auto TO Creation)

Purpose: Convert released TRs → TOs using putaway strategy Execution: Nightly (e.g., 23:00) — if fails, goods stuck in receiving Monitor: SM37 (job log) or LS12 (TO creation report)

Table LTBK (TR header):

• LGNUM, TRID (TR number)
• TDRTY (01=putaway, 02=picking, 03=replenish)

5. Putaway & Picking Strategies

Putaway Strategy (LS0N)

Determines destination bin for incoming stock.

Issue: "Putaway directs to wrong bin"

Root Cause: Strategy misconfiguration or bin full Check: LS0N → strategy assignment; SE16N → LQUA: LGMNG vs LTCAP Fix: Increase capacity (LS03N) OR change strategy (LS0N) OR manual override (LT01)

Picking Strategy (LS20)

Issue: "Picking TO shows 'No stock available' despite inventory"

Root Cause: Stock in wrong section or strategy mismatch Check: SE16N → LQUA: locked status? Strategy allows section? SE16N → LTAP: which bins picked? Fix: Move stock via TO (LT01) OR override strategy (LT01 manual) OR unlock section (LS16)

6. WM-MM Integration (Goods Receipt → Warehouse)

Complete Flow

PO (ME21N) → GR (MIGO 101, MVT 101) → Material doc (MKPF/MSEG)
  ↓
If WM active: TR created (LTBK, putaway)
  ↓
Putaway strategy applied (LS0N)
  ↓
LB10 batch: TR → TO (LTAK/LTAP)
  ↓
RF execution (LT0G) → TO confirmed (LT0A)
  ↓
Stock in LQUA, available for sales/picking

Config: Activate WM (LS19 - Goods Movement Parameters)

• KZLTAP: Auto-create TR on GR? X = yes
• KZLTAU: Auto-create TO from TR? X = yes (if LB10 running)
• KZLTPE: Two-phase picking? X = pick → staging → ship

Issue: "GR posted but TR never created"

Root Cause: WM not activated or storage location not assigned Check: LS17 (storage location assignment), OB8B (plant-WM), MIGO (warehouse field) Fix: LS17 → create assignment OR repeat GR

7. WM-SD Integration (Delivery → Picking)

Complete Flow

Sales Order (VA01) → Delivery (VL01N)
  ↓
Auto-create picking TR (if LPICK = X in VL0N)
  ↓
LB10: TR → picking TO (strategy 01=FIFO typical)
  ↓
RF picking (LT0G) → staging bin
  ↓
PGI (VF01) → invoice created

Config: Enable Picking in Warehouse

VL0N (delivery type):

• LPICK: Picking required? X = yes

OB8C (storage location):

• LSORT: Use for WM? X = yes

Issue: "Delivery created, picking TR not auto-created"

Root Cause: LPICK disabled or storage location not WM-enabled Check: VL0N (LPICK flag), OB8C (LSORT flag), SE16N → LTBK (any TR created?) Fix: VL0N → set LPICK = X → recreate delivery

8. Physical Inventory in WM (LI01N / LI02N)

Types

Flow

LI01N (create doc) → LI04 (print sheet) → Count physical stock
  ↓
LI04 (enter results) → LI07 (post differences)
  ↓
MM doc created (401/402 MVT) → LQUA adjusted

WM PI vs MM PI

Issue: "Count sheet shows zero system qty but WM has stock"

Root Cause: LQUA (WM) ≠ MARD (MM) — movements bypassed WM Check: SE16N → LQUA (sum qtys), SE16N → MARD (compare), SE16N → MSEG (recent GI) Fix: LI07 (post adjustment) OR manual TO correction (LT01)

9. Decentralized WM (MWMII)

Simple warehouse management without bins/sections. Each plant manages own goods movement.

When to use: Multi-plant independent operations (NO bins/sections/strategies) When NOT to use: Need rack control, FIFO/LIFO, RF execution → use central WM instead

Config: SM30 → TWMII (plant-level settings)

10. ECC WM → S/4HANA Migration

Why WM Deprecated

S/4HANA has NO WM module. Replaced by:

• Embedded EWM (enhanced warehouse management with resource management)
• Stock Room Management (simplified, basic movements)

Migration Options

Key Differences (WM → EWM)

Recommendation: Use EWM for S/4HANA (see sap-ewm skill). WM 1:1 not possible.

11. Korean Logistics (한국 현장)

Typical Setup: Manufacturing / 3PL

Warehouse tiers:

• 생산창고 (production WH) ← factory GR
• 물류센터 (logistics center) ← distribution hub
• 반납창고 (return WH) ← defects

필수 기능:

• 바코드/RF 터미널: CJ, Coupang, Samsung parts (standard)
• 팔레트 관리: 식료품, 전자부품 (high-volume)
• 냉장/냉동: Separate ST with capacity limits
• 선입선출 (FIFO) 강제: 식품/의약품 — picking strategy 01 MUST be used

Example: Korean Food Distribution WH

Warehouse "PJ" (plant JP01, company 1000):
  ST 01 (rack, ambient) → Sec A1-A5 (fast-movers), Sec A6-A10 (slow)
  ST 02 (cold, 2-8°C) → Sec C1-C3 (yogurt, milk, frozen)
  ST 03 (returns) → Sec R1 (defects, quarantine)

Putaway: 02 (addition + next-empty)
Picking: 01 (FIFO — regulatory requirement)
RF Terminal: Symbol/Zebra with ZMM
Inventory: Monthly cycle count (LI03)

12. Key References

Primary Tables:

• LAGP: Warehouse master
• LTYP: Storage type
• LEIN: Storage section
• LQUA: Storage bin / quant
• LTBK: Transfer requirement
• LTAK: Transfer order (header)
• LTAP: Transfer order (lines)

Configuration T-codes:

• LS01N: Warehouse structure
• LS0N: Putaway strategies
• LS20: Picking strategies
• LS13: Cycle count params
• LS19: WM goods movement params
• LS17: Storage location assignment

Standard Response Format: Issue → Root Cause → Check (T-code + table) → Fix → Prevention → SAP Note

Last Updated: 2025 | ECC Status: Extended Support | S/4HANA: Use EWM skill