whirrwork

Robot or Human?

Security patrol

Security guard on patrol vs Autonomous patrol robot (MaaS)

Whirrwork modelled estimates, not facts. Methodology · Track record

Human · Per year$228,704Guard on site
Robot · Per year$151,754Patrol robot as a service
Payback0 months
Crossover yearnowBase-case year (earliest to latest across scenarios)

On these numbers the robot option is clearly cheaper.

United States · USD · BLS OEWS May 2025 national medians by SOC occupation

Run your numbers

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Workload
Assumption

Patrol hours needed per day (24 = round the clock).

Assumption

Operating hours per day.

Assumption

Days per month (every day).

Assumption

Active months per year.

People
U.S. Bureau of Labor Statistics

BLS OEWS May 2025 national median hourly wage, SOC 33-9032.

U.S. Bureau of Labor Statistics

Wages and salaries were 70.0% of total employer compensation cost for private industry workers in June 2026 (ECEC), so total cost = wage / 0.70.

ilostat.ilo.org

Nominal 4.4% a year, 2015-2025 (ILOSTAT hourly earnings).

Assumption

One guard-hour covers one patrol-hour.

Robot
Assumption

One robot-hour covers one patrol-hour of a defined route (outdoor lots, perimeters).

Knightscope

Midpoint of Knightscope's marketed $6-$12 per robot-hour on an annual 24/7 contract.

Assumption

Site survey, connectivity and alarm-centre integration.

Assumption

Contract length in years.

Assumption

Share of hours the robot patrols (charging is scheduled).

Assumption

Hours lost to faults, covered by a guard.

Assumption

Share of guard hours spent on things a patrol robot cannot do: responding, access control, talking to people. A person stays on call for these.

Assumption

Remote-monitoring minutes per robot-hour (watching alerts, often shared across sites).

Assumption

Included in the contract.

Assumption

Electricity price per kWh (USD). Check your bill; energy is rarely a big line.

Money
Assumption

Annual financing / discount rate. Nobody publishes yours; 8% is a round mid-2026 commercial borrowing guess.

Assumption

Years in the NPV comparison.

Assumption

Share of a human service price that is labour (rises with wages). Used to escalate and to adjust US service prices to other countries.

Assumption

Share of a robot service price that is labour (pilot, technician). The rest is equipment, which learning curves make cheaper.

Assumption

Share of a lease or RaaS fee that pays for hardware (learns down). The rest is service and support (moves with wages).

Download these results (CSV)

Results

OptionPer monthPer yearPer unit (patrol hour)UpfrontPaybackBreak-even utilisation5-year NPV vs baseline
Human Guard on site Baseline $19,059$228,704$26.12— — — —
Robot Patrol robot as a service $12,646$151,754$17.33$3,000 0.5 months 1%
Utilisation 72%
 $362,527

What moves the answer most

Each bar shows the 5-year NPV of the best robot option when one input moves to the low or high end of its range, with the rest held at your values.

5-year NPV vs baseline: Patrol robot as a service5-year NPV vs baseline: Patrol robot as a serviceWork that stays humanlow value: 0.15 → $474,997high value: 0.6 → $221,940Workloadlow value: 8 → $118,842high value: 24 → $362,527Hourly wagelow value: 14.624000000000002 → $247,322high value: 21.936 → $477,732Supervisionlow value: 2 → $406,667high value: 20 → $208,037Subscription per robot-hourlow value: 6 → $432,694high value: 12 → $292,361Employer on-cost multiplierlow value: 1.2790000000000001 → $302,063high value: 1.579 → $422,992Work lost to failureslow value: 0 → $382,390high value: 0.1 → $316,180Financing and discount ratelow value: 0.05 → $391,318high value: 0.12 → $328,427Wage growth per yearlow value: 0.0236 → $341,663high value: 0.0636 → $384,192$362,527low valuehigh valueSource: Whirrwork Robot-or-Human model v1.0.0 (whirrwork.com/tools/robot-vs-human/security-patrol/). Modelled estimate, not a fact.

Cost per unit to 2035

Real terms (today's money). Robot hardware follows Wright's law; wages follow each country's history. Shaded band: robots-slow to robots-fast scenarios. Whirrwork modelled estimates, not facts.

ChartHuman cost per unit (Base), Robot cost per unit (Base), Robot cost per unit (Robots fast), Robot cost per unit (Robots slow). Source: Whirrwork Robot-or-Human model v1.0.0 (whirrwork.com/tools/robot-vs-human/security-patrol/). Modelled estimate, not a fact.$0.00$10.00$20.00$30.002026202720282029203020312032203320342035USD / patrol hourscenario rangeHuman cost per unit (Base)Robot cost per unit (Base)Robot cost per unit (Robots fast)Robot cost per unit (Robots slow)Source: Whirrwork Robot-or-Human model v1.0.0 (whirrwork.com/tools/robot-vs-human/security-patrol/). Modelled estimate,…

Crossover year: now

What the spreadsheet misses

Safety
A robot cannot intervene, give first aid or de-escalate. It detects and reports; someone still responds.
Quality
Robots never skip a round and record everything; guards notice context.
Flexibility
Guards do access control, deliveries, lost children. Robots patrol.
Edge cases
Stairs, rain, crowds and vandalism are known problems. One famously drove into a fountain.
Customer experience
Visible deterrence cuts both ways: some visitors like it, some find it creepy.
Jobs and redeployment
In practice robots replace overnight rounds on big lots; people move to response and monitoring.
Regulation
Licensing applies to guards, not robots; recording and privacy law applies to robot cameras (GDPR in the EU/UK).

Related

Sources on this page

  1. Knightscope robots: effective $6-$12 per hour on an annual 24/7 Machine-as-a-Service contract Knightscope, 2026-10 · vendor
  2. Occupational Employment and Wage Statistics, May 2025 (median hourly wage by occupation) U.S. Bureau of Labor Statistics, 2025-05
  3. Employer Costs for Employee Compensation, June 2026: wages and salaries 70.0% of private-industry compensation (series CMU2020000000000P) U.S. Bureau of Labor Statistics, 2026-06
  4. Mean nominal hourly earnings of employees by sex and occupation (ISCO-08), DF_EAR_EHRA_SEX_OCU_CUR_NB ILOSTAT (International Labour Organization), from national labour force and earnings surveys, 2025
  5. Labour cost levels by NACE Rev. 2 activity (lc_lci_lev): Germany 2022-2025, total labour cost vs wages and salaries per hour Eurostat, 2025
  6. Rates and thresholds for employers 2025 to 2026 (employer Class 1 NIC 15% above £5,000) HM Revenue & Customs, 2025-04-06
  7. 令和6年賃金構造基本統計調査 (Basic Survey on Wage Structure 2024), table 1 by occupation Ministry of Health, Labour and Welfare, Japan (via e-Stat), 2024-06
  8. Average monthly earnings of employees by sex and economic activity, DF_EAR_EMTA_SEX_ECO_CUR_NB ILOSTAT (International Labour Organization), 2022
  9. Average annual wage of employed persons in urban units in 2024 (by position and by region) National Bureau of Statistics of China, 2025-05-20
  10. Euro foreign exchange reference rates (cross rates to USD), via Frankfurter European Central Bank, 2026-10-23
  11. Wright, T. P. (1936). Factors affecting the cost of airplanes. Journal of the Aeronautical Sciences, 3(4), 122-128 Journal of the Aeronautical Sciences, 1936
  12. Nagy, B., Farmer, J. D., Bui, Q. M., & Trancik, J. E. (2013). Statistical basis for predicting technological progress. PLoS ONE, 8(2), e52669 (62 technologies; Wright's law among the best hindcasters; errors grow with horizon) PLoS ONE, 2013