Airport Ground Support Equipment worked example

GSE Spare Parts Buffer Days with critical gse spare parts on hand of 210 parts: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop critical gse spare parts on hand to 210 parts, then walk the calculation through step by step. Estimate protected spare-parts coverage for airport GSE from inventory on hand, expected daily usage, and safety factor.

The inputs for this scenario

  • Critical GSE spare parts on hand: 210 parts (the input this scenario stresses; the baseline uses 420)
  • Expected daily spare parts usage: 18 parts/day (held at the documented default)
  • Lead-time and criticality safety factor: 1.4 x (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Base spare parts days on hand = critical spare parts on hand รท expected daily spare parts usage.
  • Protected GSE spare parts buffer works out to 8.33 buffer days at these inputs, and this is the headline figure for the scenario.
  • Base spare parts days on hand works out to 11.67 days at these inputs.
  • Critical GSE spare parts on hand works out to 210 parts at these inputs.
  • Expected daily spare parts usage works out to 18 parts/day at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where critical gse spare parts on hand sits at 420 parts and the headline result is 16.67 buffer days, this scenario comes in 50% below the baseline at 8.33 buffer days.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to critical gse spare parts on hand, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It assumes steady average daily usage; a single AOG-style event or seasonal traffic spike can burn through the buffer far faster than the average predicts.

Results at a glance

  • Protected GSE spare parts buffer: 8.33 buffer days (headline result)
  • Base spare parts days on hand: 11.67 days
  • Critical GSE spare parts on hand: 210 parts
  • Expected daily spare parts usage: 18 parts/day

Run it with your numbers

  • To rerun this with your own numbers, open the live GSE Spare Parts Buffer Days calculator, set critical gse spare parts on hand to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.