AMR ROI: Calculating Labour Savings and Fleet Costs

For a simple annual return on investment (ROI) from autonomous mobile robots (AMRs), divide annual cash costs actually avoided, less annual fleet operating and support costs, by the initial installed investment. Test those savings against on-time deliveries, manual recovery and production interruptions before treating released driving hours as a financial return.

Defining AMR labour savings and fleet costs

An autonomous mobile robot, or AMR, creates value when material reaches the operation that needs it, within the required time and with fewer resources overall. A completed robot mission does not establish that outcome. The wrong rack, a late delivery or a transfer completed with an operator’s assistance can make a fleet dashboard look productive while the factory continues paying for the previous transport process. The financial baseline therefore needs a defined workflow, an accepted delivery and a comparable production schedule.

Start with the existing route and its actual paid hours. Separate driving, loading, waiting and recovery, then establish which activities the proposed system will remove. Multiply avoidable hours by the relevant employment cost, but count cash savings only when overtime, temporary labour, vacancies or other expenditure actually fall. Staff redeployed to production represent additional capacity whose value needs separate evidence. OTTO’s AMR business-case guidance identifies shift patterns and employment costs alongside the vendor’s equipment and implementation costs; these inputs need to describe the same workflow and period.

The initial investment should include the complete quoted installation: robots, attachments, chargers, infrastructure, commissioning, integration and training. Recurring expenditure should include software, maintenance, energy, replacement components and the staff retained to supervise or recover the service. Internal engineering hours and parallel manual operation during commissioning also consume resources. Keep the cash-flow model distinct from the accounting presentation. Depreciation affects reported profit but is not an additional purchase payment, and a lease or service contract changes the payment schedule rather than removing the underlying operating dependency.

Calculating annual return and simple payback

Consider an illustrative calculation, unrelated to any disclosed customer installation. Assume an installed investment of £500,000, 12,000 annual transport hours theoretically released and an avoidable labour cost of £30 an hour. The gross opportunity is £360,000. If only 8,000 hours actually leave paid staffing or overtime, realised labour savings are £240,000. With £90,000 of annual operating and support costs, the net annual cash benefit is £150,000. Simple payback is £500,000 divided by £150,000, or approximately 3.3 years; the simple annual return on the initial investment is 30%.

That example excludes tax, financing, residual value and the time value of money, and assumes a full year at steady operation. A delayed rollout would change the cash profile. If the same fleet avoids only 5,000 paid hours, the net annual benefit falls to £60,000 and simple payback rises to approximately 8.3 years. The change comes from staffing assumptions alone. A capital approval should therefore identify the person responsible for each staffing change and the date it can occur, then model the ramp-up separately from steady operation.

Fleet sizing, accepted deliveries and interruption costs

Fleet sizing can alter both sides of that calculation. OTTO’s fleet-sizing guidance describes assumptions about travel distance, docking, charging, traffic rules and the distribution of throughput. A factory with sharp peaks cannot automatically use an estimate based on evenly distributed demand. Extra robots may provide useful reserve capacity, but shared aisles, chargers and transfer stations can remain constraints. Ask the supplier to show the same workload under peak demand, a robot outage and the traffic restrictions that will apply during ordinary production.

Measure cost per accepted delivery alongside total annual benefit. For an operating-cost comparison, divide recurring transport and support expenditure by deliveries received correctly within the agreed service window. For a full economic comparison, add a consistently defined annual capital charge or use discounted project cash flows. State which approach is used. Record manual recovery hours, receiving-cell waiting and failed transfers separately, so that a lower reported unit cost cannot conceal work transferred to production staff. Compare equivalent routes, payloads, shifts and output rather than unrelated fleet totals.

Production interruption deserves an explicit assumption rather than an arbitrary penalty. Estimate the incremental loss associated with transport failures using the factory’s own evidence, accounting for buffers, recovery and whether lost output can be made up. Do not count both the full value of delayed production and the cost of recovering that same production without checking for overlap. The acceptance period should include routine staffing after intensive commissioning support has withdrawn. Otherwise, supplier engineers may temporarily provide the availability that the final operating budget cannot sustain.

The broader robotics deployment economics framework connects utilisation, integration and lifecycle cost across applications. For AMRs, the decisive comparison is narrower: the cost of maintaining the agreed material flow before and after the change. The premium research on Nissan’s AMRs and fleet availability develops the distinction between announced role reductions and the supporting capacity needed to preserve production. It provides a deployment case, not a transferable savings rate for another factory.