Sap Wm

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

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: BoxLogoDev
• Source: BoxLogoDev/sapstack
• License: MIT

Install and usage instructions live in the source repository linked above.