Oil, Gas & Energy Equipment Manufacturing worked example

Long-Lead Casting Buffer with daily usage of castings of 600 units / day: a worked example

Suppose daily usage of castings falls to 600 units / day. This page works the full calculation at that level so you can see exactly which result moves and by how much. Size the buffer stock for long-lead castings and forgings, such as valve bodies and pump casings, from daily usage, supplier lead time, and a safety stock quantity, so planners can cover the lead time and protect the build schedule.

The inputs for this scenario

  • Daily usage of castings: 600 units / day (the input this scenario stresses; the baseline uses 1,200)
  • Supplier lead time: 85 days (held at the documented default)
  • Safety stock quantity: 1.1 units (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Cycle stock = daily usage of castings × supplier lead time.
  • Protected days of supply works out to 6.42 days at these inputs, and this is the headline figure for the scenario.
  • Unprotected days works out to 7.06 days at these inputs.
  • Inventory works out to 600 pieces at these inputs.
  • Daily usage works out to 85 pieces / day at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where daily usage of castings sits at 1,200 units / day and the headline result is 12.83 days, this scenario comes in 50% below the baseline at 6.42 days.
  • It computes required casting buffer inventory as lead-time demand plus safety stock, and shows how many days your current on-hand actually protects. 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

  • Protected days of supply: 6.42 days (headline result)
  • Unprotected days: 7.06 days
  • Inventory: 600 pieces
  • Daily usage: 85 pieces / day

Run it with your numbers

  • To rerun this with your own numbers, open the live Long-Lead Casting Buffer calculator, set daily usage of castings to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.