Shelf gap model

Model your shelf gap

An illustrative model of the revenue and gross profit exposed to shelf execution errors. It starts from the base case in The Perfect Store Gap. Replace any assumption with your own and every step of the arithmetic updates.

Assumptions

Your chain

One category, one store

Transactions that include at least one product from the category.

What those transactions spend in the category, not the whole basket.

Execution

The share of category trading that happens while an execution error is on the shelf.

The share of that exposed trading that is lost rather than kept through substitution.

Across 50 stores, per year Illustrative

€567,000

gross profit at risk

€1.62 million revenue at risk

Illustrative results
Category sales per store, per year€648,000
Modeled sales loss5%
Revenue at risk per store, per year€32,400
Gross profit at risk per store, per year€11,340
Revenue at risk per store, per trading day€108

The arithmetic

Every result comes from four lines. Nothing is weighted, smoothed or compounded.

Category sales per store
180 transactions × €12 × 300 days = €648,000
Modeled sales loss
20% exposure × 25% severity = 5%
At risk per store
€648,000 × 5% = €32,400 revenue; × 35% margin = €11,340 gross profit
At risk across the chain
per store × 50 = €1,620,000 revenue and €567,000 gross profit

How sensitive is it?

The result moves in proportion to exposure and severity, the two assumptions that are hardest to know. The grid shows gross profit at risk across your chain for ten points either side of your values. Yours is outlined.

Gross profit at risk across the chain, per year · illustrative

What the model leaves out

It is a way to size the question, not a forecast of your results.

  • Sales kept through substitution. Severity counts only the share of exposed sales that is lost.
  • Margin changes when a shopper substitutes, and wider effects on a launch’s trajectory.
  • Promotional funding spent on displays that were not in place.
  • The cost of checking shelves, and anything gained by correcting them.
  • Compounding. The model is linear: double an assumption and the result doubles.

See your shelf gap

The model sizes the question. A pilot answers it with your categories, your stores and the shelves your shoppers actually meet.

If you have changed the model, your scenario is added to the enquiry for you to edit.