What did that job really cost?

This builds cost the way a works order actually accumulates it, rather than the way a quote estimates it.

Setup is charged once across the whole job, then spread over the units. That is why short runs of the same part cost more per unit than long ones, and why a quote built on an average never survives contact with a small order.

Scrap inflates material, labour and machine together. A 6% scrap rate does not mean 6% more material — it means you had to start enough parts to finish the order, so every input is divided by 1 − scrap rate. Rework consumes the floor twice, which is why it belongs here and not in a quality report.

Overhead is recovered as a percentage of direct labour, which is the most common basis in UK SME manufacturing. If your accountant recovers on machine hours instead, put the equivalent into the machine rate and set overhead to zero.

Margin here is gross — it does not carry selling cost, carriage or finance. The number that usually surprises people is not the cost, it is the gap between this and what was quoted.