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?

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2. Warehouse Structure (LS01N / LS03N / LQUA)

Hierarchy & Tables

Level	T-code	Definition	Table
Warehouse	LS01N	Top container, assigned to plants	LAGP
Storage Type	LS01	Physical zone (rack, yard, high-bay, flow)	LTYP
Storage Section	LS03N	Sub-zone (aisle, row)	LEIN
Storage Bin	LS03N	Individual slot (address: WH-ST-SEC-BIN)	LQUA

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

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

Key T-codes

T-code	Function	Field
LT01	Create TO manually	LGPLA (from), LGPLB (to)
LT03	Release picking TO	Qty by storage section
LT0E	Release putaway TO	Destination bin
LT0A	Confirm TO execution	Updates LQUA stock
LT0G	RF execution (handheld)	Worker mobile entry
LT04	Cancel TO	Full reversal

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)

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4. Transfer Requirement (LB01 / LB10)

Auto-Creation Triggers

Source	T-code	Type
GR	MIGO 101	Putaway TR
Delivery	VL01N	Picking TR
Production	PP	Component withdrawal TR
Inventory diff	LI07	Correction TR

Key Transactions

T-code	Function	Audience
LB01	Create TR manually	Planner
LB03	Release TR for TO	Coordinator
LB10	Auto-convert TR → TO	Batch job
LB05	TR search/list	Daily monitoring

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)

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5. Putaway & Picking Strategies

Putaway Strategy (LS0N)

Determines destination bin for incoming stock.

Strategy	Name	Best For	Logic
00	Fixed Bin	High-value A-items	Always same bin
01	High-Rack (ASRS)	High-bay volume	Empty level/aisle
02	Addition Strategy	Normal WM	Same bin + space, else next-empty
03	Next Empty	Flexible rack	Always first available
10	Manual	Special cases	Planner override

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)

Strategy	Name	Use Case
00	Fixed Bin	Slow-movers
01	FIFO	Perishables, batch-tracked
02	LIFO	Frozen goods
03	Bulk / Open	Palletized high-volume
10	Manual	Flexible picking

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)

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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

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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

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8. Physical Inventory in WM (LI01N / LI02N)

Types

Type	T-code	Scope	Frequency
Full	LI01N	All warehouse stock	Annual
Sample	LI02N	Selected sections	Quarterly
Cycle	LI03N	Material/section	Monthly/continuous

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

Aspect	WM (LI01N)	MM (LI01)
Scope	Warehouse bins (LQUA detail)	Storage locations (MARD)
Granularity	By bin	By location
Batch/Serial	Full detail	Batch-level

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)

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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)

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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

Option	Effort	Best For
ECC WM → EWM	HIGH	Large, complex warehouses
ECC WM → Stock Mgmt	MEDIUM	Small, simple operations
Keep ECC dual-run	MEDIUM	Transition period

Key Differences (WM → EWM)

ECC WM	S/4HANA EWM
Storage Type (LTYP)	Warehouse Process Type
Transfer Order (LTAK)	Warehouse Order
Putaway Strategy (LS0N)	Putaway Rule (different config)
RF (LT0G)	RF Screen (/SCWM/RFUI — new tech)
❌ Adds in EWM: Resource Mgmt, Yard Mgmt, Wave picking

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

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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)

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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

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