Build the estimate
Use one period and name each assumption.
This is a simple screening calculation, not a forecast of guaranteed savings. For a larger or longer investment, include the timing of costs and benefits, uncertainty and any discounting your finance team requires.
01
Measure the current task
Count completed instances over a representative period and time the handling, corrections and exceptions. Note quiet and busy periods. Use your actual operating weeks when annualising, rather than assuming every week has the same volume.
02
Separate money from capacity
Record spending that would actually stop or be avoided, such as a contractor charge. Record employee time released separately. An hourly valuation can help compare options, but a salary does not fall just because a task takes less time. Do not count both the wage valuation and the same spending reduction.
03
Include setup and running costs
Estimate implementation, data cleanup, testing and training, then subscriptions, usage fees, monitoring and exception handling. Record internal work as well as invoices where relevant. Check what is already included in a supplier quote so costs are not counted twice.
04
Calculate ROI, then test payback
Simple first-year ROI = (first-year benefit minus initial cost minus first-year recurring cost) / (initial cost plus first-year recurring cost) x 100. Simple payback = initial cost / net recurring benefit. Use a consistent basis for benefits and costs, and test lower volume, a slower start and higher support effort.
What remains manual
Price the work that remains.
Automation can remove a task while leaving the awkward cases with the team. Include that remaining work in the estimate.
The Government Efficiency Framework distinguishes reductions in spending from capacity released for other work. That distinction is useful here: four hours returned to a salaried colleague can improve service without changing the payroll.
Check the estimate
Costs and assumptions to write down
Exception handling: how many cases will still need review, and how long will they take?
Operating costs: subscriptions, usage charges and the time needed to monitor or repair the workflow.
Starting period: training, parallel running and a delay before benefits begin.
Change: likely process updates, connector changes and the cost of stopping or replacing the automation.
Decision
A short payback cannot make an unsafe workflow worth building.
There is no universal six-month approval rule. Decide what payback is acceptable for the investment, how reliable the assumptions are and what failure would cost. A required control may be justified for reasons other than financial return.
Fictional worked example
GBP 2,400 setup, GBP 400 net benefit a month
Assume a paid external service costing GBP 500 a month can genuinely be cancelled when the automation starts. The replacement costs GBP 100 a month, including support. Setup is GBP 2,400. All figures use the same cost basis, with no other costs assumed.
Benefits begin immediately and remain constant for 12 months. A delayed start or an uncancelled service changes the result. These are example assumptions, not a typical Mannvit outcome.
| Calculation | Amount |
|---|---|
| First-year avoided spending: 12 x GBP 500 | GBP 6,000 |
| First-year cost: GBP 2,400 + (12 x GBP 100) | GBP 3,600 |
| First-year net benefit: GBP 6,000 - GBP 3,600 | GBP 2,400 |
| First-year ROI: GBP 2,400 / GBP 3,600 x 100 | 66.7% |
| Monthly net benefit: GBP 500 - GBP 100 | GBP 400 |
| Simple payback: GBP 2,400 / GBP 400 | 6 months |
Common questions
Questions about automation ROI
For a simple first-year estimate, subtract initial and first-year recurring costs from the first-year benefit, divide by those costs and multiply by 100. Use the same period and currency throughout. Keep cash savings separate from a valuation of time released.
Divide the initial cost by the recurring benefit after recurring costs, using matching time units. If monthly net benefit is GBP 400 and setup costs GBP 2,400, simple payback is six months. This assumes benefits start immediately and stay constant.
Include setup, data preparation, testing, subscriptions, usage fees, ongoing support and exception handling. Include internal staff time where relevant, and avoid counting the same cost or benefit twice.
