Rail Signaling & Wayside Equipment worked example

Configuration Complexity with severity of an error in this configuration of 15 score: a worked example in rail signaling & wayside equipment

Push severity of an error in this configuration up to 15 score and the picture changes. This example computes every intermediate figure at that operating point. Use it when configuration complexity in rail signaling and wayside equipment needs a defensible ranking against other rail signaling and wayside equipment risks for the next review.

The inputs for this scenario

  • Severity of an error in this configuration: 15 score (raised for this scenario; the documented default is 6)
  • Likelihood of a configuration or data error: 4 score (unchanged)
  • Chance the error survives test and review: 3 score (unchanged)

Working through the calculation

  • Applying the documented formula (Configuration complexity risk score = configuration complexity severity score × configuration complexity occurrence score × configuration complexity detection score) to the inputs above produces each figure below.
  • At this operating point the engine returns 8.15 score for configuration complexity risk score, the number this scenario is built around.
  • At this operating point the engine returns 15 score for configuration complexity severity score.
  • At this operating point the engine returns 4 score for configuration complexity occurrence score.
  • At this operating point the engine returns 3 score for configuration complexity detection score.

How this compares with the baseline

  • Against the tool's baseline example, where severity of an error in this configuration sits at 6 score and the headline result is 4.55 score, this scenario comes in 79.12% above the baseline at 8.15 score.
  • It multiplies the severity, occurrence likelihood and detection difficulty of a configuration or data error into a single Risk Priority Number. 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

  • Configuration complexity risk score: 8.15 score (headline result)
  • Configuration complexity severity score: 15 score
  • Configuration complexity occurrence score: 4 score
  • Configuration complexity detection score: 3 score

Run it with your numbers

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

Last reviewed 2026-05-12.