Spread seven / Left leaf / More than the bay holds

Counts, cover and replenishment triggers

A stock figure is a claim about a shelf. The only thing that settles it is somebody standing at the shelf counting.

Specimen — order with a quantity the face will not cover

24 × storage crate, stacking, 45 L — B5

“It’s for a house move so I’d rather have them all at once than in two lots if that’s possible.”

— bay B5 holds nine on the face

The customer has asked the one question the stock figure cannot answer on its own. There may be twenty-four in the building; there are nine where the picker is going to be standing, and the rest are above, in reserve. So this order does not fail, it waits: the face is replenished from reserve before the pick note is raised, and the pick happens once.

The alternative — pick nine, raise a second note, send two parcels — is slower, costs two handovers and is exactly what the customer asked not to happen. Knowing which of the two applies means knowing what is on the face, which is a count, and what is in reserve, which is a different count.

Spread seven / Right leaf / Counts and the trigger

Three kinds of count

  • Receipt

    Against the delivery note, before anything is put away. The only count a discrepancy can be raised on.

  • Perpetual

    A few bays at a time by rotation. Face and reserve counted as two figures, because they drain differently.

  • Blind

    A second person, told neither number. A recount that knows the answer will agree with it.

“Adjusted down four” tells you nothing in a month’s time.

So an adjustment is written with the count that produced it and the name of that count type. “Adjusted down four, blind recount, after a perpetual count disagreed” is the start of an answer instead of the end of one.

Right leaf / Reading a bay at a glance

Cover, read as a screen

Cover is the plainest figure on the floor: units on the bay divided by units sold a day, which gives days. The bay tickets carry it as a dot screen rather than a number, because a number on a ticket is out of date the moment it is printed and a screen is only ever a category. Four steps, coarse to fine, and the picker who notices a bay has dropped a step tells the desk.

The screen on a bay ticket
ScreenReads asWhat is done
Comfortable coverNothing
Approaching the pointWatched on the next perpetual count
At or under the pointOrder raised that day
Inside lead time, nothing on orderDesk told, and the listing checked before it sells what is not there

The steps are a reading, not a measurement. The arithmetic underneath them is below, and it is the arithmetic a desk should be able to do on the back of the delivery note.

Tool / Replenishment-trigger sheet

When the bay has to be reordered

Four figures go in. The sheet prints the reorder point, the cover left on the bay and the day the point is reached, with each step of the arithmetic beside it.

Trigger sheet, step by step
StepWorkingUnits
Sold while the order is in transit18 a day × 9 days of lead time162
Held back for the days that run hot18 a day × 4 safety days72
Reorder point162 + 72234
Cover on the bay now240 on hand ÷ 18 a day13.3 d
Units above the point240 − 2346
Triggerin 1 day at this rate1 d

Guide only — the sheet assumes the rate you type is the rate that holds, and nothing sells at a flat rate. It is a way of seeing how close a bay is to its point, not a forecast. A count beats it every time.

Right leaf / What the figures cannot do

Where the trigger stops working

The reorder point assumes a steady rate, and nothing sells at a steady rate. A range that moves in bursts — because it is seasonal, or because one order can take a month of ordinary demand in a single line — crosses its point without warning, and the sheet is no help at all. For those the number watched is not cover but the largest single line the bay has ever had to serve.

The second limit is the lead time, which is not a property of this floor at all: it is what somebody else does. The honest way to hold it is as a figure that has been observed rather than one that has been quoted. Until there is enough observation to hold a figure the safety days do the work, and they are set generously and written down as a guess.