Six fields almost nobody fills in, and which way each one bends the cost

These six inputs share one property: leave them empty and the sheet still produces a perfectly plausible number, with no warning of any kind. Each one bends the result a different way — and five of the six bend it so the product looks CHEAPER than it is, which is the dangerous direction, because nobody audits a comfortable number.

1. Material yield

Not all purchased material becomes product. What is lost to chips, to end-of-roll remnants, to trim, to rejected stock — you already paid for it.

The system divides consumption by the yield rate, so the lower the yield the higher the true material cost. Blank means 100%, which asserts that nothing is ever lost.

Where the number comes from: material actually issued for a batch, divided by the material contained in the units actually delivered. That figure reconciles against goods issue notes — an estimate does not.

Not the same as recovery value

Two different things that get confused. Yield describes how much material is LOST; recovery value describes how much of that loss is SOLD or REUSED. A part can lose fifteen percent and recover most of it.

2. Personal allowance for operators

Stopwatch time is pure working time. Real people need breaks, need to leave the station, and hit interruptions that cannot be designed away — and every one of those minutes is still paid.

The system multiplies normal time by one plus this allowance. Blank asserts that operators work continuously through a shift, which happens nowhere.

3. Machine allowance

The same idea for equipment: machines stop for tool changes, for cleaning, for adjustment, for waiting. This allowance brings occupied machine time in line with what actually happens.

It moves three figures at once — depreciation, shop overhead recovered per machine hour, and energy — because all three scale with real running time.

Where the number comes from: compare machine hours available in a shift against machine hours that actually produced, from the machine log or the shift handover book.

4. Energy

Two inputs: connected load and price per unit. The system multiplies them by running time to get the energy cost carried by that volume.

Where the numbers come from: load from the machine plate, price from the invoice — and use the tariff band you are actually billed at, not the cheapest band on the published schedule.

5. Units per pack

This is the largest distortion of the six and it runs opposite to the rest. You enter the price of a pack; unless you say how many units the pack holds, the system assumes one.

The same mechanism covers anything bought by the group: bags, trays, pallets, rolls of film. Enter the price of the whole unit and how many products it holds, and let the system divide.

6. Fixed cost per lot

Plenty of costs are charged per occurrence rather than per unit. A subcontractor applies a minimum lot charge; a truck costs the same whether it runs full or half empty; a setup takes the same time regardless of batch size.

Enter two figures: the cost per lot and the units per lot. The system divides down to the unit and — more importantly — rounds the number of occurrences UP, because there is no such thing as two-fifths of a setup or half a truck.

Why these six stay empty

Not because they are difficult. Because leaving them empty produces no visible failure: the sheet still adds up, a result still appears, no warning line lights up. The person entering data has no way to notice anything is missing.

And because five of the six make the cost look CHEAPER, they never surface the way an odd-looking figure does. A number that comes in low does not attract suspicion — it makes people pleased.

The reliable fix: work through all six once, for your first part, and record your plant's own values. Most of them do not change from part to part, so one pass covers you for a long time.