Waste-to-Energy Equipment worked example

Spare Parts Buffer with critical spare consumption rate of 3,000 units / day: a worked example in waste-to-energy equipment

Push critical spare consumption rate up to 3,000 units / day and the picture changes. This example computes every intermediate figure at that operating point. Use it when spare parts buffer in waste-to-energy equipment is being sized for a buffer or safety stock review.

The inputs for this scenario

  • Critical spare consumption rate: 3,000 units / day (raised for this scenario; the documented default is 1,200)
  • Supplier replenishment lead time: 85 days (unchanged)
  • Buffer safety factor: 1.1 units (unchanged)

Working through the calculation

  • Applying the documented formula (Spare parts buffer cycle stock = spare parts buffer daily usage × spare parts buffer lead time) to the inputs above produces each figure below.
  • At this operating point the engine returns 32.09 days for protected days of supply, the number this scenario is built around.
  • At this operating point the engine returns 35.29 days for unprotected days.
  • At this operating point the engine returns 3,000 pieces for inventory.
  • At this operating point the engine returns 85 pieces / day for daily usage.

How this compares with the baseline

  • Against the tool's baseline example, where critical spare consumption rate sits at 1,200 units / day and the headline result is 12.83 days, this scenario comes in 150% above the baseline at 32.09 days.
  • It computes the days of supply your current spare-parts inventory protects, plus the cycle stock and total inventory needed to cover supplier lead time and a safety buffer. 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

  • Protected days of supply: 32.09 days (headline result)
  • Unprotected days: 35.29 days
  • Inventory: 3,000 pieces
  • Daily usage: 85 pieces / day

Run it with your numbers

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

Last reviewed 2026-05-12.