Loaded cost, not salary

A person costing €50,000 a year does not cost €50,000. Add employer taxes, pension, equipment, software licences, the floor they stand on and the proportion of management attention they consume. The multiplier is commonly somewhere between 1.25 and 1.7 depending on the country and the role.

Then divide by productive hours, not contracted ones. Nobody performs the process for 1,800 hours a year; they perform it between other things, and the switching is part of what it costs.

Use your organisation's own figure if it has one. A number finance recognises beats a better number they have never seen.

Time saved is not money saved

This is where these business cases get dishonest, usually without meaning to.

Saving four minutes on a task performed twenty times a day gives back eighty minutes. That is only money if the eighty minutes goes to something valuable, and only cash if it eventually means fewer people or more output. Frequently it becomes eighty minutes of slightly less rushed work — which is genuinely good and is not a line in a budget.

Say which one you are claiming. "Releases 6.5 hours a week of capacity" is honest and defensible. "Saves €18,000 a year" usually is not, and the person who has seen three of these before will know.

Compute the honest annual figure

Turn instances, minutes and loaded cost into an annual capacity figure — and make it refuse to overstate. Automation rarely eliminates a task entirely; there is exception handling, checking, and the occasional manual run.

Annual hours the automation could release

Using your own volume, your own timing and an honest residual. Put the residual you assumed in the note; it is the number somebody will challenge.

The number comes back small

The honest figure is 140 hours a year — about three weeks of one person's time. Your build is six weeks.

The number in the room

You now know something about this process that the people who perform it daily probably do not.