EV Charging Infrastructure Manufacturing worked example

Service Parts Buffer with usable service-parts inventory of 2,400 parts: a worked example in ev charging infrastructure manufacturing

What does the result look like when usable service-parts inventory reaches 2,400 parts? The full calculation is worked below with real intermediate numbers. a service parts planner needs to know whether spares cover field demand and supplier lead time risk

The inputs for this scenario

  • Usable service-parts inventory: 2,400 parts (raised for this scenario; the documented default is 960)
  • Average daily service demand: 24 parts / day (unchanged)
  • Service criticality risk multiplier: 1.25 x (unchanged)

Working through the calculation

  • Applying the documented formula (Protected service-parts days = usable service-parts inventory ÷ average daily service demand ÷ service criticality risk multiplier) to the inputs above produces each figure below.
  • At this operating point the engine returns 80 days for protected service-parts days of supply, the number this scenario is built around.
  • At this operating point the engine returns 100 days for unadjusted service-parts days of supply.
  • At this operating point the engine returns 2,400 parts for usable service-parts inventory.
  • At this operating point the engine returns 24 parts / day for average daily service demand.

How this compares with the baseline

  • Against the tool's baseline example, where usable service-parts inventory sits at 960 parts and the headline result is 32 days, this scenario comes in 150% above the baseline at 80 days.
  • A figure at this level is achievable when usable service-parts inventory is genuinely sustained, not just peaked for a shift. It uses average daily demand and ignores demand variability and replenishment lead time, so a single regional failure cluster can exhaust the buffer faster than the average implies.

Results at a glance

  • Protected service-parts days of supply: 80 days (headline result)
  • Unadjusted service-parts days of supply: 100 days
  • Usable service-parts inventory: 2,400 parts
  • Average daily service demand: 24 parts / day

Run it with your numbers

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

Last reviewed 2026-05-12.