GlossaryKind of term: Cost and economicsOne-off costs
What are one-off costs?
One-off costs are incurred once for a batch or a part design, such as setup, programming or a fixture, however many parts follow.
One-off costs are costs that do not recur with every part. They come in two kinds. Per-batch costs return with every run, repeat orders included: setup for each clamping and often the first-article check. Per-design costs fall, in principle, once per part or revision: programming, a dedicated fixture, special tooling, a full first-article inspection report. Divided by the number of parts, they give the one-off share per part.
How do one-off costs work in practice?
How you recover per-design costs is a commercial choice: as a separate item on the quote, spread over the first batch, or spread over expected total demand. The last gives a lower first price but carries a risk if follow-on orders do not come. On one-offs and small batches, one-off costs can be the largest part of the cost; on large batches, material and machining time usually weigh more. On a repeat order part of them falls away, provided revision, machine and workholding are unchanged.
What are one-off costs often confused with?
One-off costs are not setup time: setup time is a duration per setup, one-off costs are the amount the batch or part design carries for it, plus whatever else is incurred once. Nor are they the fixed costs of the business, such as rent and depreciation: those sit in the rates and overheads, not in an order.
Frequently asked questions
Why show the one-off share apart from cost per part?
Because it changes with quantity and most of the rest does not. Seen on its own, it lets you explain what a larger quantity does to the price, and choose deliberately how to recover programming or a fixture.
Do you charge one-off costs again on a repeat order?
Setup usually yes, because it returns with every batch. Programming and a fixture usually not, as long as revision, machine and workholding stay the same. A drawing change can bring part of them back.
Should one-off costs appear separately on the quote?
They can, particularly for a fixture or special tooling. It shows the customer what is paid once and keeps a follow-on order from looking expensive. The alternative is to spread them over the first batch.