Roofing, Siding & Exterior Building Products worked example

Weather Delay Inventory Buffer with finished product inventory on hand of 3,000 units / day: a worked example

Push finished product inventory on hand up to 3,000 units / day and the picture changes. This example computes every intermediate figure at that operating point. Use it when weather delay inventory buffer in roofing, siding and exterior building products is being sized for a buffer or safety stock review.

The inputs for this scenario

  • Finished product inventory on hand: 3,000 units / day (raised for this scenario; the documented default is 1,200)
  • Daily install/ship usage: 85 days (unchanged)
  • Weather-delay safety factor: 1.1 units (unchanged)

Working through the calculation

  • Applying the documented formula (Weather delay inventory buffer cycle stock = weather delay inventory buffer daily usage × weather delay inventory 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 finished product inventory on hand 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 protected days of supply by dividing inventory by daily usage and adjusting for a weather-delay safety factor. 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 Weather Delay Inventory Buffer calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.