The number to watch
Stock ageing against shelf life. Chemical products expire, and a tin sitting for two years is a warranty claim rather than an asset. The movement report over any period shows exactly which lines are not turning, and those are the ones to clear at cost while they still have life. This is the trade where the difference between stock and dead stock is a date, and reviewing it quarterly is what keeps the difference small.
Litres, kilos and rolls on one bill
A single job takes liquid membrane by the litre, a cementitious compound by the kilo and sheet membrane by the roll or the square metre. Holding the unit on each item means an applicator buying a full set gets one bill with correct arithmetic, rather than three calculations done while he waits. Coverage per litre or per kilo is worth recording on the item too, because that is the number he will ask you for.
The season is short and the ordering decision is made once
Demand concentrates in the weeks before the monsoon and collapses afterwards. That makes stocking a single decision taken in advance, and last season's movement report is the only sensible basis for it. Ordering short means missing the weeks that matter; ordering long means chemicals sitting through a year with a shelf life running down. The report answers both.
Shelf life and old stock
Chemical products expire, and a tin that has been on the shelf for two years is a warranty claim waiting to happen rather than stock. Tracking movement per item shows what is not turning over, which is where the risk sits. Clearing slow lines at cost before they age out is a better outcome than discovering them when a customer complains about a failed application.