Industrial Sensors & Instrumentation worked example

Sensor Failure Rate at 1.15% target annual failure rate: a worked example

Push target annual failure rate up to 1.15% and the picture changes. This example computes every intermediate figure at that operating point. Use this when tracking field reliability, benchmarking failure rates across sensor types or suppliers, deciding whether a design change or supplier switch is needed, or reporting reliability KPIs to management.

The inputs for this scenario

  • Confirmed sensor failures: 7 failures (unchanged)
  • Total installed sensor population: 800 sensors (unchanged)
  • Target annual failure rate: 1.15 % (raised for this scenario; the documented default is 1)

Working through the calculation

  • Applying the documented formula (Failure rate = confirmed failures / installed population x 100) to the inputs above produces each figure below.
  • At this operating point the engine returns 0.88 % for field failure rate, the number this scenario is built around.
  • At this operating point the engine returns 0.27 points for gap to reliability target.
  • At this operating point the engine returns 7 count for confirmed sensor failures.
  • At this operating point the engine returns 800 count for total installed population.

How this compares with the baseline

  • Against the tool's baseline example, where target annual failure rate sits at 1% and the headline result is 0.88 %, this scenario lands almost exactly on the baseline at 0.88 %.
  • It divides confirmed failures by the installed sensor population to give a percent failure rate, then subtracts your target to show the gap. The value of this scenario is the size of the gap it exposes: that gap, priced out over a year, is the budget you can justify spending to close it.

Results at a glance

  • Field failure rate: 0.88 % (headline result)
  • Gap to reliability target: 0.27 points
  • Confirmed sensor failures: 7 count
  • Total installed population: 800 count

Run it with your numbers

  • Every input above is editable in the live Sensor Failure Rate calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.