In most warehouses empty containers are counted once a month, alongside the inventory, yet containers go missing daily: one leaves on a shipment, does not come back, and nobody notices.
- Opening (at shift handover): number of ready, clean containers.
- Movement (at each dispatch and return): container numbers going out and coming back.
- Closing (after the last vehicle is back and returns are processed): containers left.
The calculation: add returns to the opening count, subtract dispatches and compare with the closing count. When the numbers differ the container is usually not lost; it is waiting at a customer, in the wash bay or in the body of another vehicle, and those three places are where to look first. Keep them out of the missing stock, in a separate list with container number, last movement time, location and follow-up owner. The hardest is the container at a customer: the number written at delivery is the only fact that closes the evening gap.
The outgoing and incoming shifts count together, because a count by one person does not show which shift the gap arose in. Pass open gaps to the next shift in a signed handover note.
The decision to buy more containers rests on the number ready in the morning, not the total pool: a pool of a hundred does not mean working with a hundred every morning.
