How Much Does Warehouse Automation Actually Cost to Pay Back?
Worked result: A 4,000 sqm two-shift Singapore warehouse handles 1,280 transport moves per day. In this model, six AMRs handle 960 moves and the retained crew handles 320. Capital is SGD 828,000; steady gross annual savings are SGD 336,600 and annual operating cost is SGD 60,000. Steady net benefit is SGD 23,050 per month. With no savings in months 1-3, half savings in months 4-6 and operating cost throughout, cash break-even arrives in month 42.
The calculation starts with work capacity, then connects the remaining manual work to staffing and cash savings. Each table provides the inputs needed to rerun the model for another facility.
Model basis. Prices, move times, utilisation and staffing are illustrative inputs. Populate the same fields with a WMS move log, time study, payroll data and scoped equipment quotations to produce a site-specific case. The model separates capacity released from labour cost actually removed or avoided.
What Does the Worked Scenario Assume?
The facility and the work it does
| Input | Value in this model | Where you get your own number |
|---|---|---|
| Floor area | 4,000 sqm (about 43,000 sq ft) | Lease document |
| Operating pattern | 2 shifts x 8 h, 250 days per year | Roster |
| Internal transport moves | 640 per shift, 1,280 per day | WMS move log, peak week |
| Average manual move | 3.6 min door to door, including pick-up and drop | Time study on 30 moves |
| Transport headcount | 12 operators, 6 per shift | Payroll, transport cost centre only |
| Operator productive time | 384 min of a 480 min shift (80%) | Shift observation |
The baseline closes: 6 operators x 384 productive minutes = 2,304 operator-minutes per shift, divided by 3.6 minutes per move = 640 moves. Reconcile any difference against measured waiting, concurrent tasks and move definitions. The same distinction between scheduled time and productive output matters when calculating OEE from separate loss categories.
The equipment scope being modelled
Six transport-class AMRs, 500 kg payload, running point-to-point pallet and cage moves between inbound, storage and despatch.
| Input | Value in this model |
|---|---|
| AMR available transport time | 16 h per day per unit (960 min), matching the two-shift demand window |
| Modelled cycle per move | 6.0 min including docking and traffic queueing |
| Moves per AMR per day | 160 |
| Fleet capacity, 6 units | 960 moves per day |
| Demand | 1,280 moves per day |
| Residual manual moves | 320 per day, plus exception handling |
| Retained operators | 4 (2 per shift) |
| Transport roles removed | 8 |
Each shift retains 160 manual moves x 3.6 minutes = 576 operator-minutes. Two operators provide 768 productive minutes, leaving 192 for exceptions and other assigned work. The fleet model assumes charging is arranged outside the 16-hour transport window. Validate that schedule, peak queues and station availability in the fleet trial; any lost availability reduces the 960-move capacity and changes the residual staffing requirement.
What Does the Equipment Scope Cost?
This model allocates SGD 80,000 per AMR, then prices software, infrastructure and integration separately. A project quotation should name payload, top module, docking interface, safety options, charger quantity and licence terms so the vehicle line items describe comparable equipment.
| Line item | Basis | Illustrative cost (SGD) |
|---|---|---|
| 6 transport AMRs, 500 kg class | 6 x 80,000 | 480,000 |
| Fleet management software and WMS interface licence | one-off licence | 60,000 |
| Charging stations, electrical work, Wi-Fi coverage | 3 chargers plus site electrical | 45,000 |
| Integration, interface development, commissioning | project engineering | 120,000 |
| Operator and maintenance training, documentation | initial delivery | 15,000 |
| Subtotal | 720,000 | |
| Contingency at 15% | 108,000 | |
| Total capital, month 0 | 828,000 |
AMR hardware represents 58 percent of this model’s capital. Software, site work, engineering, training and contingency make up the balance. Compare the complete scope using the guide to scope and responsibility when comparing system integrators.
Annual running cost:
| Cost component | Basis | Annual (SGD) |
|---|---|---|
| Maintenance and spares | 5% of hardware value | 24,000 |
| Software support subscription | vendor | 12,000 |
| Electricity, fleet and chargers | metered | 6,000 |
| Internal support | 0.2 FTE technician share | 18,000 |
| Total annual operating cost | 60,000 |
What Is the Annual Benefit, Line by Line?
First, calculate the loaded cost of one role using the applicable payroll category. The contribution percentages below are explicit example assumptions.
| Component | Monthly (SGD) | Source of the number |
|---|---|---|
| Gross monthly wage | 2,600 | Model input; replace with payroll |
| Employer CPF at 17% | 442 | Example contribution assumption; use the applicable rate for the employee |
| Other employer-borne cost at 12% | 312 | SDL, work injury insurance, medical, PPE, supervision share |
| Loaded monthly cost | 3,350 | 3,354 rounded to the nearest SGD 10 for the model |
| Loaded annual cost | 40,200 |
For Work Permit roles, calculate wage, the applicable levy and other employment costs separately, without the example’s CPF contribution. Use the resulting total for those roles; it can differ from the local-worker assumption in either direction.
| Benefit line | Basis | Annual (SGD) |
|---|---|---|
| 8 transport roles not backfilled | 8 x 40,200 | 321,600 |
| Transport-related overtime removed | about 640 h at 1.5x an SGD 15.60 base hour | 15,000 |
| Error, mis-pick and damage reduction | not booked | 0 |
| Recovered floor space | not booked | 0 |
| Gross annual benefit | 336,600 | |
| Less annual operating cost | (60,000) | |
| Net annual benefit | 276,600 | |
| Net monthly benefit | 276,600 / 12 | 23,050 |
Error reduction and space recovery are booked at zero here. Add them using measured avoided losses, rent actually avoided or incremental contribution from usable capacity. Keep those benefits separate from labour savings and avoid counting the same capacity gain twice.
When Does the Investment Actually Break Even?
Simple payback is 828,000 / 276,600 = 2.99 years, about 36 months. It is a steady-state comparison; the cash-flow model also needs the timing of savings and operating costs.
The example books zero gross savings in months 1-3, half the steady gross savings in months 4-6, and full savings from month 7. Operating cost is SGD 5,000 per month from month 1. Net cash flow is therefore minus SGD 5,000, then SGD 9,025, then SGD 23,050 per month across those phases.
| Period | Net cash flow booked | Cumulative cash (SGD) |
|---|---|---|
| Month 0 | (828,000) capital | (828,000) |
| Months 1-3, dual running | (5,000) per month | (843,000) |
| Months 4-6, 50% gross savings | 9,025 per month | (815,925) |
| Months 7-12 | 23,050 per month | (677,625) |
| Months 13-18 | 23,050 per month | (539,325) |
| Months 19-24 | 23,050 per month | (401,025) |
| Months 25-30 | 23,050 per month | (262,725) |
| Months 31-36 | 23,050 per month | (124,425) |
| Months 37-40 | 23,050 per month | (32,225) |
| Month 41 | 23,050 | (9,175) |
| Month 42 | 23,050 | +13,875 break-even |
Over 60 months, cumulative net cash after the initial investment is SGD 428,775, or 51.8 percent of the capital committed. Year 1 contributes SGD 150,375 and each of years 2-5 contributes SGD 276,600. Discounting those year-end cash flows at 10 percent gives a five-year NPV of approximately SGD 105,782. This calculation excludes tax, financing cash flows and terminal value; add them as separate lines when required by the investment model.
Which Input Breaks the Business Case First?
Rerunning the model with one input changed at a time, everything else held:
| Change from base case | Net monthly benefit (SGD) | Break-even |
|---|---|---|
| Base case | 23,050 | Month 42 |
| Loaded labour cost 4,000 in place of 3,350 | 28,250 | Month 35 |
| AMRs at 55,000 per unit | 23,675 | Month 34 |
| Only 6 roles removed or avoided | 16,350 | Month 57 |
| Only 5 of 12 roles removed or avoided | 13,000 | Month 70 |
A 31.25 percent reduction in AMR unit price shortens payback by eight months in this model. That scenario reduces capital to SGD 655,500, including contingency, and annual operating cost to SGD 52,500 because maintenance is tied to hardware value. Removing five roles instead of eight extends payback by 28 months. All rows retain the same savings-ramp pattern and charge their operating costs from month 1.
That has a practical consequence. Before signing capital, get written agreement on what happens to the 8 roles: attrition without backfill, redeployment to work that would otherwise have been hired for, or contract non-renewal. “Staff will be redeployed to higher-value tasks” is not a financial benefit unless a req somewhere else closes as a result. If nobody will commit to that in writing, model the project at five roles and see whether it still clears your hurdle rate.
Which Equipment Type Should You Model?
Compare AGV and AMR alternatives against the same transport duty, stations and traffic. Fixed-route guidance can use floor references or other navigation methods; route changes, site work and support should be priced for the selected system. ASRS adds a storage-density and retrieval decision. The AMR vs AGV guide covers transport selection, and the warehouse and intralogistics page connects storage, transport and end-of-line scope. For robotic palletizing, use the same cash-flow method with measured case handling and retained operator work.
Rebuild the capital split for each equipment type; the 58 percent hardware share above belongs to this six-AMR example.
For a goods-to-person project, model accepted order lines and retained replenishment work, not only robot moves. A container presentation that supports several picks changes the capacity assumption; the same order mix must be used in the equipment trial and financial model.
Which Tasks Need an Explicit Budget Owner?
Allocate these tasks to the engineering, infrastructure, training or support lines and identify any additional cost:
- Safety assessment and zone design. Mobile robots sharing aisles with pedestrians and manual forklifts need a risk assessment under ISO 12100, scanner field configuration and traffic rules. Budget engineering time for it. The standards framework is set out in the notes on collaborative and mobile robot safety standards and the machine safety and compliance work that goes with it.
- WMS and ERP interface ownership. Someone has to own work order handover, status feedback and exception codes on both sides of the interface, through go-live and every subsequent WMS upgrade.
- Network segmentation. A fleet on the same flat network as office IT is a finding waiting to happen; segmentation and access control are described in the IEC 62443 industrial cybersecurity overview.
- Map and layout maintenance. Every rack move is a map update. Small cost, permanent cost.
- Process redesign and SOPs. The workflow around the transport step changes, and the training that goes with it is not a one-off.
Use the 15 percent contingency for uncertainty after the known scope has been costed. Update the base estimate when a task is identified so the same work is not counted in both the engineering allowance and contingency.
The first of them does more than consume contingency. The zoning outcome feeds back into the throughput assumption, because where an aisle turns out to be unsuitable for mixed pedestrian and vehicle traffic the fleet either routes around it, which lengthens the cycle per move and lowers moves per day, or the site funds a physical separation, which raises capital. The sensitivity table above compares labour-cost, vehicle-price and roles-removed scenarios. To model lower fleet output, recalculate residual manual work and retained staffing, then rerun the cash flow with those labour savings. Zone design is therefore an input to fleet sizing, and that is the argument for commissioning the assessment before the fleet count is fixed. The traffic-rule and zoning detail for a shared floor is on the AMR and AGV integration page.
How Do You Run This on Your Own Numbers?
Six steps, in this order:
- Pull one peak week of move data from your WMS: moves per shift, distance bands, and how many are exceptions. Peak week, because the fleet gets sized on peak.
- Time thirty manual moves, door to door, including waiting. Do not use a standard time.
- Compute utilisation and close the loop. Operators x productive minutes / minutes per move should reproduce your observed move count. If it does not, fix that before going further.
- Size the fleet against peak demand, then subtract. Fleet capacity below demand is fine and normal; what matters is what the residual manual work requires in headcount.
- Build loaded labour cost from payroll: CPF, levy where applicable, insurance, supervision.
- Book only benefits someone will sign for. Then apply the ramp and read the break-even month off the cumulative column.
Motionwell has delivered AGV installation and AMR-based transport work in Singapore. A QA lab automation programme, re-ordered across four consecutive years, combines AMR transport, a collaborative robot, vision and server-based task scheduling; the QA lab automation case study describes that phased scope. A pilot provides measured move times, exception work and staffing outcomes to refine the full rollout model.
What Should You Send to Get This Modelled?
To have this calculation run against your facility, contact the Motionwell engineering team with four things: one peak week of WMS move data, your current transport headcount by shift, your loaded labour cost per operator, and your facility layout. That is enough to size a fleet and return a payback model in the format above, with every assumption listed so your finance team can challenge each one.