Shrink, and how it is measured

A retailer knows what it bought and what it sold. The difference is what it should have. A physical count says what it does have. Shrink is the gap, and it therefore contains theft, damage, receiving errors, mis-scans at the register, misallocated returns, vendor shortages and plain data entry mistakes, all mixed together.

Because it is a residual, shrink rises whenever process discipline slips anywhere in the chain, not only when theft rises. Attributing the whole figure to one cause is the most common error in reading it.

An error at the register affects one unit. An error at receiving affects a carton, a pallet or a shipment, and it propagates: the system believes it holds units it never received, allocates them, and reports them as available. A buyer downstream then writes an order against an inventory file that includes phantom stock, which is one of the ways an ATS file drifts from reality.

Cycle counting rather than annual counts, so errors surface while their cause is still identifiable. Receiving discipline, particularly scanning at the carton level against the purchase order. And reconciliation between systems, because the largest discrepancies tend to live at the seams between a warehouse system and a merchandising system rather than inside either one.