Sizing a container fleet from average daily dispatch can hide units waiting for return or washing. Derive need from actual cycle and order records.

Track a container's cycle

Link issue, customer wait, return, wash, drying, repair and readiness dates to container ID or batch record. Identify where steps take longer.

Count simultaneous demand on a peak day. For the busiest order day, count containers needed in field use, awaiting customer return, in washing, under repair and ready to dispatch separately. Avoid counting the same unit in two stages.

Find the stock gap from records

Compare required quantities with physical inventory and confirmed orders. Consider the gap against new purchase, faster returns or a revised wash plan; do not add an assumed growth rate.

Recalculate if return time or product mix changes. Add calculation date and operating period used to the purchasing file.