9  Replenishment in practice

Keywords

Replenishment, Warehouse management system, Pick face, Storage optimization, Inventory management

Replenishment

  • Replenishment moves the required products and quantities into pick locations (Richards 2018).
    • An empty pick slot can delay an order or cause a lost sale.
    • Late replenishment increases shortages, picking time, and cost per pick.

Replenishment timing

  • A real-time WMS can trigger replenishment from current inventory and order data:
    • Replenish the actual order quantity before the next order wave.
    • Replenish when pick-face inventory reaches a defined level.
  • The trigger changes operating risk:
    • Early replenishment can overfill pick faces and disrupt FIFO.
    • Late replenishment can empty a pick face before reserve stock arrives.

Replenishment methods

  • Move products directly from inbound receiving to the pick face when this removes an intermediate handling step.
    • Plan the quantity to prevent overfilling.
    • Split pallet layers to match expected pick quantities.
  • Without a real-time WMS:
    • Size pick faces from predicted demand per day or shift and the location’s cubic capacity.
    • Train staff to report replenishment needs to the responsible supervisor or forklift driver.

Example: A replenishment heat map

  • In the fashion industry, clothing racking systems are used to store hanging garments on beams or tubes to prevent wrinkling or damage.
  • Tiered picking shelves with mezzanines and walkways increase storage capacity while retaining direct access to goods.
  • Restocking is often done chaotically, with items placed in any available location.
  • A heat map can show inventory by location so employees can find empty replenishment positions.

Example of clothing racking storage system by Mecalux (2023).

Coordinating picking and replenishment

  • Simultaneous picking and replenishment can:
    • Cause safety issues if forklifts and pedestrian pickers work in the same aisle.
    • Lead to confusion if both are at a location at the same time.
  • Solutions include:
    • Incorporating multiple picking locations for the same SKU
    • Using storage handling systems that better separate the picking and replenishment processes (e.g., A frames, carton live storage, or flow racking)
    • Carrying out the two activities at different times of the day if feasible.

Carton flow racking uses inclined platforms with rollers, separating storage and picking aisles to reduce congestion and improve workflow (Mecalux 2025).

References

Mecalux. 2023. “Warehouse Clothing Racking: How to Store Garments.” Supply Chain & Warehouse Logistics Blog, January 26. https://www.mecalux.com/blog/warehouse-clothing-racking.
Mecalux. 2025. “Live Storage for Picking.” Mecalux. https://www.mecalux.com/picking/live-storage-for-picking.
Richards, Gwynne. 2018. Warehouse Management: A Complete Guide to Improving Efficiency and Minimizing Costs in the Modern Warehouse. 3rd Edition. Kogan Page Ltd.