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Lesson 1 of 5

Why a warehouse system

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Every SAP S/4HANA company tracks stock. The question is how precisely. Inventory management knows that Contoso Motor Co. has 420 alternators (CMC-ALT-100) in plant 1710, storage location 171A. A warehouse management system also knows that 40 of them are on rack bin 02-03-1, 380 are in bulk storage, and that a forklift driver has a task to move 20 to the packing area. That extra precision costs effort to set up and run, so the first question is always whether a site needs it.

Inventory management: stock by storage location

Inventory management (IM) records quantities and values per material, plant and storage location. SAP's learning material describes the storage location as a logical separation of stock within a plant, not necessarily a physical one. Goods receipts, goods issues and transfers are posted as material documents. Where exactly the goods sit inside the storage location is not recorded: a stockroom clerk finds them by knowledge, labels or a spreadsheet. SAP Learning confirms you can run inventory management on its own for a plant and storage location, without any warehouse number.

With inventory management only, a goods receipt updates the storage location total; where the clerk puts the goods is never recorded.
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Warehouse management: stock by bin, moved by tasks

Warehouse management adds a physical model of the building. A warehouse number represents a physical warehouse, which can span several buildings, and is linked to one or more plant and storage location combinations. Inside it are storage types (such as racking, bulk or a goods receipt zone) and storage bins, the actual places where stock sits. Every movement inside the warehouse is a warehouse task from a source bin to a destination bin, grouped into warehouse orders as work packages for warehouse staff.

With warehouse management, a receipt of Lakeside regulator kits becomes a warehouse task, and the stock is known by bin once the worker confirms it.
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Plant 1710 DetroitOrganizational unit where stock is valued and planned
Storage location 171ALogical stock separation; inventory management stops here
Warehouse numberThe physical warehouse, linked to plant and storage location
Storage typeAn area with its own rules: racking, bulk, goods receipt zone
Storage binThe exact place: aisle, stack, level. Warehouse management tracks stock here
From plant to bin. Inventory management stops at the storage location; warehouse management continues to the bin.
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QuestionInventory management onlyWarehouse management
Where is the stock?In storage location 171AIn bin 02-03-1, 40 pieces, in a handling unit
Who moves it and when?Not recorded in the systemWarehouse tasks assigned to people or resources
How is putaway decided?By the clerkBy rules for storage types and bins
How is stock counted?Per storage locationPer bin, including handling units
Set-up and running effortLowHigher: bins, rules, devices, training
Inventory management versus warehouse management for the same alternators.
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When a warehouse system pays off

  • Many materials and bins, where people can't reliably remember locations.
  • High volumes of picking and putaway, where directed tasks save walking and errors.
  • Traceability needs: batches, serial numbers, handling units, customer audits.
  • Space pressure, where rules for putaway and replenishment use the building better.
  • Automation such as conveyors or automated storage, which needs exact control.

What would you do?

Chicago's plant manager asks whether Chicago should also get bin-level warehouse management "because Detroit has it." Chicago has 300 parts in one stockroom and two clerks. What is the best response?

How Contoso's Detroit storage locations map to the warehouse

Storage locationContentManaged in EWM?Why
171RReceived on dock, not yet put awayYes (warehouse 1710)Stock is visible but not yet available for sale
171AAvailable for sale; deliveries pick hereYes (warehouse 1710)Bin-level control for picking and counting
171BFinished alternators received from production (movement 101)No, IM levelPosted outside EWM, then put away into 171A
171SSpare parts and rotor stockNoSmall stockroom; IM is enough
171LLine-side stock at ASSY-10NoSupplied by transfer; planned by a reorder-point MRP area

One plant, several levels of control: only 171R and 171A are linked to EWM warehouse number 1710.

Key points
  • Inventory management tracks stock by plant and storage location; it can run on its own.
  • Warehouse management adds a warehouse number, storage types and bins, and moves stock with warehouse tasks.
  • Bin-level control pays off with volume, many materials, traceability, space pressure or automation.
  • Choose per site: Contoso's Detroit and Chicago need different answers.

Check your understanding · not graded

Lesson check

  1. 1. What does inventory management track that warehouse management refines?

  2. 2. What is a warehouse task?

  3. 3. Which situation most clearly calls for bin-level warehouse management?

  4. 4. A tester posts a goods receipt for regulator kits to 171S and no warehouse task appears. What is the most likely explanation?