Lupus Consulting
Get in touch
Back to Overview

SAP EWM Storage Control: POSC vs LOSC Explained

SAP Extended Warehouse Management (EWM) storage control orchestrates complex warehouse movements by defining the sequence of process steps for putaway, stock removal, and internal transfers. Storage control in EWM is implemented through two complementary approaches: Process-Oriented Storage Control (POSC) and Layout-Oriented Storage Control (LOSC). For IT and warehouse managers, understanding the differences and interaction between POSC and LOSC helps ensure efficient, error-free material flows.

Quick Answer

  • POSC (Process-Oriented Storage Control) defines the logical sequence of warehouse process steps — the "what" (for example: unloading, counting, quality inspection, putaway). POSC is driven by the Warehouse Process Type (WPT) for inbound and the Warehouse Order Creation Rule (WOCR) for outbound and exclusively works with Handling Units (HUs).
  • LOSC (Layout-Oriented Storage Control) determines the physical routing — the "how" — using intermediate storage bins or identification points to adapt flows to the warehouse layout (for example: transfer points, elevators, or staging areas).
  • SAP EWM evaluates and executes POSC first to decide what must happen, and then LOSC to determine the physical path to carry it out.
Storage-control sequence: POSC determines what happens to the handling unit; LOSC determines how it travels there.

What is Process-Oriented Storage Control (POSC)?

  • Definition: POSC sets the logical sequence of process steps for warehouse tasks — essentially the business process or workflow that must be performed on a handling unit.
  • Key concepts and terms:
    • Handling Unit (HU): A packed unit (for example a pallet, box, or container) managed as a single entity in EWM.
    • Warehouse Process Type (WPT): Drives POSC behavior for inbound processes.
    • Warehouse Order Creation Rule (WOCR): Drives POSC behavior for outbound processes.
  • Important constraint: POSC works exclusively with Handling Units (HUs). Items not managed as HUs are not supported by POSC in EWM.
  • Typical use cases: Incoming goods workflows that require inspection, counting, deconsolidation, or staged staging steps defined as discrete process steps.

What is Layout-Oriented Storage Control (LOSC)?

  • Definition: LOSC governs the physical movement of material through the warehouse layout by routing via intermediate storage bins, transfer points, or identification points.
  • Purpose: To adapt material flow to physical constraints, equipment reachability, and building topology (for example, routing a pallet to a transfer point if the receiving forklift cannot access a high-rack location).
  • Typical use cases: Multi-equipment handoffs, flows requiring elevators, conveyors, or staging points where the physical layout dictates intermediate stops.

How POSC and LOSC interact

  • Order of evaluation:
    1. EWM evaluates and executes POSC first to determine the required logical process steps (the "what").
    2. EWM then applies LOSC to determine the physical route (the "how") to reach the work center or storage bin required by POSC.
  • Benefit of the combined approach: Separating logical process definition (POSC) from physical routing (LOSC) enables flexible, maintainable workflows that respect both business process requirements and physical warehouse constraints. See source [1] for overview guidance.

Common pitfalls

  • Incomplete or inadequate definition of process steps leads to inefficient flows and unclear task sequencing.
  • Overlooking the requirement that POSC needs Handling Units (HUs) — a common configuration error when items are not HU-managed.
  • Failing to model physical layout constraints in LOSC can result in tasks that require impossible movements, causing bottlenecks or system errors.

FAQ

  • What is the fundamental difference between POSC and LOSC?

    • POSC concerns the logical process (the "what" to do: inspection, packing, deconsolidation), while LOSC concerns the physical routing (the "how" to move material: via transfer points, elevators, conveyors).

  • Does SAP EWM Storage Control support non-Handling Unit managed items?

    • No. Process-Oriented Storage Control (POSC) requires Handling Units (HUs). If items are not HU-managed, POSC cannot be applied.

  • How do POSC and LOSC work together in EWM?

    • EWM determines the next logical step via POSC and then uses LOSC to find the physical path to the work center or storage bin that completes that step.

Related Articles