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? --- ## 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 --- ## 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)