Downtime cost: the invoice that lands at the customer

What it is made of

The largest item is almost always lost contribution margin: what the plant would have produced in that time and at what margin. On top of it come the costs that keep running while nothing is produced — labour, energy, depreciation, tied-up input material. Where delivery commitments exist, penalties or substitute procurement follow, and in the process industry restart and scrap losses on ramp-up.

Harder to quantify but real: the reputational effect of repeated outages, and the management capacity tied up doing nothing else while a fault is live.

Planned versus unplanned

The difference is bigger than the duration suggests. A planned shutdown can be placed in a weak order period, bundled with other work, and run with prepared material and staff. An unplanned one hits the organisation cold: parts missing, technicians elsewhere, production stopped with no alternative. That is why predictability carries economic value in its own right — independent of whether total downtime falls.

What that means for the service business

If downtime costs a multiple of the repair, the operator is not negotiating over the price of the part. They are negotiating over time to resolution. That shifts the whole offer: availability becomes the product, not the spare part. Response time, first-time fix rate and remote diagnosis turn into commercial arguments — and a service contract with credible commitments sells at a price that material cost could never justify.

For the manufacturer, the customer's downtime arithmetic is therefore the most important number in the sales conversation — and usually the only one the customer already knows.

A practical approximation

Downtime hours multiplied by contribution margin per operating hour, plus continuing fixed cost per hour, plus one-off restart and penalty cost per event. The calculation is rough, but it can be built together with the customer in half an hour — and it makes every discussion about service pricing factual.