Maintenance & Reliability worked example

Spare Parts Stockout Risk with downtime severity if part is unavailable of 4.5 score: a worked example

Suppose downtime severity if part is unavailable falls to 4.5 score. This page works the full calculation at that level so you can see exactly which result moves and by how much. Score spare stockout risk from downtime severity, stockout likelihood, and detection difficulty.

The inputs for this scenario

  • Downtime severity if part is unavailable: 4.5 score (the input this scenario stresses; the baseline uses 9)
  • Likelihood of a stockout occurring: 6 score (held at the documented default)
  • Difficulty of detecting low stock early: 7 score (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Risk score is a weighted combination of downtime severity, stockout likelihood, and detection difficulty.
  • Stockout Risk Score works out to 5.65 score at these inputs, and this is the headline figure for the scenario.
  • Downtime Severity works out to 4.5 score at these inputs.
  • Stockout Likelihood works out to 6 score at these inputs.
  • Detection Difficulty works out to 7 score at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where downtime severity if part is unavailable sits at 9 score and the headline result is 7.45 score, this scenario comes in 24.16% below the baseline at 5.65 score.
  • It blends downtime severity, stockout likelihood, and detection difficulty into one weighted risk score that ranks spares for tighter stocking control or alternate sourcing. When the numbers land here, the stressed input is the lever to work; the walkthrough above shows exactly how much each output recovers as it climbs back toward the baseline.

Results at a glance

  • Stockout Risk Score: 5.65 score (headline result)
  • Downtime Severity: 4.5 score
  • Stockout Likelihood: 6 score
  • Detection Difficulty: 7 score

Run it with your numbers

  • To rerun this with your own numbers, open the live Spare Parts Stockout Risk calculator, set downtime severity if part is unavailable to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.