Calculating sales volumes in general warehousing systems

Calculating sales volumes in general warehousing systems

After one of my recent posts, I was asked what an outer quantity was. This term is common in warehousing and logistics. So many business applications assume that you sell things by quantity, and that you just count the number in vs the number out.

But that’s not how it works.

A system that’s useful for these tasks, understands way more than that. The terms unit, inner, outer, shipper, layer, and pallet refer to different levels or units of packaging and organization in the supply chain. Here’s a breakdown of each term:

Unit

  • Definition: A unit is typically the smallest single item that is sold or handled at the retail level. It’s generally not used for sales in a warehouse. It can be a single product or SKU (stock-keeping unit).
  • Example: One simple toothbrush, one box of cereal, or one pair of shoes.

Inner

  • Definition: An inner is often a package that holds a number of units. It’s often what is put on a shelf at the retail level. It’s also generally not used for sales in a warehouse.
  • Example: A display or sales package that holds 20 toothbrushes.

Outer

  • Definition: An outer refers to a secondary level of packaging that typically contains multiple units (items) of a product. It’s often the packaging level used for bulk storage and transportation to prevent damage and ease handling.

  • Example: A cardboard box (or carton) that holds 24 inners of toothbrushes (i.e., 24 x 20 = 480 toothbrushes), or just directly holds units when inners aren’t used (e.g., 24 bottles of shampoo)

    Shipper

  • Definition: A shipper is a type of outer packaging designed for shipping purposes. It’s similar to an outer but often refers to a specific box or container that is used for organizing products for shipment to a retailer, distributor, or customer.

  • Example: A corrugated box (shipper) that holds several outer boxes or smaller units, often used for bulk shipping to a retailer. Often, shippers aren’t used, and just outers (i.e., cartons) are used.

    Layer

  • Definition: A layer refers to a specific arrangement or level of items within a larger container, often used when stacking goods on pallets. Layers help organize the goods so they can be easily handled, transported, or counted.

  • Example: If a pallet holds 4 boxes in each row, and there are 5 rows stacked on top of each other, each of those rows would be considered a layer. Each layer contains a set number of outer boxes or goods. This can be helpful when counting items on a pallet that isn’t full. For example, in the warehouse bay, there are 4 pallets and 1 incomplete pallet with 3 layers.

    Pallet

  • Definition: A pallet is a flat, often wooden or plastic structure used to stack and transport multiple layers of outer packaging or goods. It makes it easier to handle heavy loads, move them with a forklift, and store them efficiently in a warehouse.

  • Example: A pallet might contain several layers of boxes, and each box might contain multiple units of a product.

Example of All Together:

  • Unit: One can of drink.
  • Inner: A package with 6 cans of drink attached to each other.
  • Outer: A cardboard box containing 72 cans of drink (12 inners).
  • Shipper: A larger box that holds multiple cartons for bulk shipping to a retailer.
  • Layer: A single row of boxes stacked on a pallet.
  • Pallet: A flat surface holding several layers of drink cartons, ready for transportation or storage.

Each level represents a different stage of organization in the warehousing process, helping to ensure products are efficiently stored, tracked, and shipped.

Database Columns

You’ll still have the normal database columns like:

OrderedQuantity, PickedQuantity, SuppliedQuantity (or ShippedQuantity)

Note: I’ve also had people ask what a PickedQuantity is. That’s the number that have been “picked” from the bulk stock and placed into an area where an order is being prepared. But they have not been shipped out yet.

But you’ll also often have columns that record how many units there are in each level. For example:

UnitsPerInner (or InnerQuantity), UnitsPerOuter (or OuterQuantity), UnitsPerShipper (or ShipperUnits), UnitsPerLayer (or LayerQuantity), UnitsPerPallet (or PalletQuantity).

And you might instead, have columns that show a hierarchy:

UnitsPerInner, InnersPerOuter, OutersPerShipper, ShippersPerLayer, LayersPerPallet

2025-03-01