Deciding what to buy next
A mug has three hundred units available and has recently sold ten units a day. The supplier usually takes forty days to deliver. At that rate, the stock lasts thirty days, so placing a purchase today may still leave ten days without supply.
That first calculation is useful, but the buyer needs to check the demand behind it, purchases already on the way, and the supplier’s ordering requirements before deciding what to do.
Understand what the history measures
Units ordered describes demand on order dates. Units shipped describes goods sent on shipment dates. An order placed in September and shipped in October appears in those months for different reasons.
For purchasing, order history can help reveal demand even when fulfillment is delayed. Shipment history helps explain what actually left stock. Comparing the two can identify a backlog, but the buyer must follow the relevant orders to establish what remains outstanding.
A stock snapshot records a quantity at a point in time. Three hundred units on Monday and two hundred and ninety on Tuesday do not add up to five hundred and ninety available units. Receipts, shipments, and adjustments explain the change between those positions.
Check whether recent demand is representative
Days of supply estimates how long stock will last at a chosen demand rate. The mug’s three hundred units at ten a day give thirty days of supply.
Look at what produced that rate. A promotion may have temporarily increased sales. A large retailer purchase may be unlikely to repeat. A period out of stock may have prevented customers from buying, making recorded sales lower than the demand the business could have served.
Consistent product attributes help here. The buyer can compare the mug with similar products or earlier seasonal ranges while keeping the individual SKU’s position visible.
Put expected supply on the calendar
Lead time is the time needed to obtain more stock. Allow for the stages that matter to the purchase, including production, transport, and receiving.
Check existing purchases before ordering again. A delivery due in two weeks could cover the mug’s immediate shortage; one due in two months would not. Its destination also matters if the demand is being fulfilled from another building.
Available stock already accounts for existing commitments. Avoid subtracting those same orders again when adding an estimate of further demand. The planning question is how the position changes as additional demand and expected receipts occur.
Choose a feasible quantity
A reorder threshold identifies a stock position that needs buying attention. Turning that signal into a purchase requires supplier minimums, case quantities, cash, and storage space to be considered.
A price break for a thousand mugs may reduce unit cost while leaving the business holding several months of stock. The buyer needs to compare that saving with the cash committed and the risk that demand changes.
For the immediate gap, the options might include an earlier partial delivery, another supplier, or a later promise to customers. Record the agreed quantity and dates on the purchase order, and retain the demand assumptions used. When the goods arrive, the buyer can compare the result with the plan and make the next purchase with better information.