A week in the life of one stock record

Inventory software can feel abstract, so here is one item. Meet interior primer, white, one gallon. It lives on shelf B-02. It sells about 3 gallons a day. This is its week, and every number in it is made up.

Monday and Tuesday: crossing the line

Monday morning the primer has 30 gallons on hand. The reorder point is 27, from the formula: 3 gallons a day, 5 days to deliver, 12 as a cushion. Three gallons go out on Monday. The shelf drops to 27, and the item shows as low.

Tuesday, Amir looks at the low-stock list, sees the primer, checks that no open purchase order exists, and places one for 24 gallons. The order is now a document with an expected date. Everyone who looks at the item can see that more is coming.

Wednesday to Friday: the wait

For five days the primer sells at its usual pace. By Friday morning only 12 gallons are left, which is precisely the cushion. The delivery truck arrives at ten.

The driver unloads 17 gallons. The order said 24. 'Balance to follow,' says the delivery note, which has no date. Amir counts the cans, writes the shortage on the driver's copy, and records a receipt for 17.

Record what came. The rest of the order stays open and visible.

On hand goes from 12 to 29. The purchase order now shows 7 still due. Nobody has to remember that, because it is on the order.

Friday afternoon: spoken for

A contractor phones to say he needs 4 gallons for a job on Monday. Rather than leave a sticky note, Amir reserves them. On hand stays at 29, but available drops to 25, which is what Priya sees if she is asked for primer on Saturday.

Saturday: a cracked lid

While restocking the shelf, Priya finds a can with a cracked lid and primer in the crease. She sets it aside and blocks one gallon, so it cannot be sold. On hand is still 29. Blocked is 1. Available is now 24.

Sunday: the count

It is count day for the A items. Priya counts the primer without looking at the system: 28 gallons on the shelf. The record says 29. One gallon is missing, and the difference is the cracked can, which she took to the skip but never wrote off.

The correction is a single adjustment of minus 1, with the reason 'damaged'. The history now reads like a diary: order, partial receipt, reservation, blocked, count, adjustment. If anyone asks on Monday why the primer is 28 instead of 29, the answer is on the screen.

What the week shows

• Every change had a reason: an order, a delivery, a sale, a count.
• The short delivery did not vanish. It stayed on the order.
• On hand, reserved, blocked and available told four different truths at the same time.
• The count found a real gap and traced it in a minute.