williamcorrea23 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-ewmskill) 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:
- ECC 6.0 (which EhP?) or S/4HANA already?
- Warehouse network: single, multi, or 3PL outsourced?
- RF terminal / barcode capability active?
- Current issue: process bottleneck, data accuracy, integration, or migration planning?
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) orD(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
| 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)
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)
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)
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
| 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)
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
| 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.
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