CMMS, EAM & Spare Parts Management worked example

Spare Parts Min Max at 140% target service-level buffer: a worked example

Push target service-level buffer up to 140% and the picture changes. This example computes every intermediate figure at that operating point. a maintenance or asset-management team needs to set min-max levels that protect uptime without tying up unnecessary MRO inventory for a spare parts min-max review

The inputs for this scenario

  • Average spare parts demand per day: 6.5 parts / day (unchanged)
  • Maximum replenishment lead-time horizon: 45 cycles (unchanged)
  • Target service-level buffer: 140 % (raised for this scenario; the documented default is 125)
  • Storeroom inventory record accuracy: 95 % (unchanged)

Working through the calculation

  • Applying the documented formula (Gross spare parts min max = average spare parts demand per day × maximum replenishment horizon) to the inputs above produces each figure below.
  • At this operating point the engine returns 389 units for usable spare parts min max, the number this scenario is built around.
  • At this operating point the engine returns 293 units for gross spare parts min max.
  • At this operating point the engine returns -117 units for spare parts min max loss from availability or service-factor limits.
  • At this operating point the engine returns 20.48 units for spare parts min max loss from data, accuracy, or acceptance gaps.

How this compares with the baseline

  • Against the tool's baseline example, where target service-level buffer sits at 125% and the headline result is 347 units, this scenario comes in 12% above the baseline at 389 units.
  • It calculates a gross min-max stock level from daily demand and lead-time cycles, then a usable level after applying your service-level buffer and storeroom record accuracy. 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

  • Usable spare parts min max: 389 units (headline result)
  • Gross spare parts min max: 293 units
  • Spare Parts Min Max loss from availability or service-factor limits: -117 units
  • Spare Parts Min Max loss from data, accuracy, or acceptance gaps: 20.48 units

Run it with your numbers

  • Every input above is editable in the live Spare Parts Min Max calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.