Rail Signaling & Wayside Equipment worked example

Relay Test Capacity at 99% expected test bench uptime: a worked example

What does the result look like when expected test bench uptime reaches 99%? The full calculation is worked below with real intermediate numbers. Use it when relay test capacity in rail signaling and wayside equipment is being asked to take on more work and you need to know if there is room.

The inputs for this scenario

  • Relays tested per test cycle: 4 units / cycle (unchanged)
  • Available test cycles in the period: 480 cycles (unchanged)
  • Expected test bench uptime: 99 % (raised for this scenario; the documented default is 90)
  • Expected relay first-pass yield: 97 % (unchanged)

Working through the calculation

  • Applying the documented formula (Gross relay test capacity = relay test capacity output per cycle × available relay test capacity cycles) to the inputs above produces each figure below.
  • At this operating point the engine returns 1,844 units for good relay test capacity, the number this scenario is built around.
  • At this operating point the engine returns 1,920 units for gross relay test capacity.
  • At this operating point the engine returns 19.2 units for relay test capacity downtime loss.
  • At this operating point the engine returns 57.02 units for relay test capacity yield loss.

How this compares with the baseline

  • Against the tool's baseline example, where expected test bench uptime sits at 90% and the headline result is 1,676 units, this scenario comes in 10% above the baseline at 1,844 units.
  • A figure at this level is achievable when expected test bench uptime is genuinely sustained, not just peaked for a shift. It treats uptime and yield as flat averages, so a bench with erratic downtime or a bad batch can miss the good-capacity figure in any single period.

Results at a glance

  • Good relay test capacity: 1,844 units (headline result)
  • Gross relay test capacity: 1,920 units
  • Relay test capacity downtime loss: 19.2 units
  • Relay test capacity yield loss: 57.02 units

Run it with your numbers

  • Every input above is editable in the live Relay Test Capacity calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.