Security, Fire & Life Safety Products worked example

Warranty Reserve at 3.45% expected field failure rate over warranty term: a worked example in security, fire & life safety products

What does the result look like when expected field failure rate over warranty term reaches 3.45%? The full calculation is worked below with real intermediate numbers. A finance partner closing the books uses this to size the warranty accrual for a shipped cohort of fire and security devices.

The inputs for this scenario

  • Fire and life-safety units under warranty: 8,000 units (unchanged)
  • Cost per warranty replacement or service event: 95 $/unit (unchanged)
  • Expected field failure rate over warranty term: 3.45 % (raised for this scenario; the documented default is 3)
  • Administrative and claims-handling reserve floor: 2,500 $ (unchanged)

Working through the calculation

  • Applying the documented formula (Reserve = units x cost per event x expected failure rate% + admin floor) to the inputs above produces each figure below.
  • At this operating point the engine returns 28,720 $ for total warranty reserve cost, the number this scenario is built around.
  • At this operating point the engine returns 3.59 $ / piece for warranty reserve cost per unit.
  • At this operating point the engine returns 26,220 $ for variable warranty reserve cost.
  • At this operating point the engine returns 2,500 $ for fixed warranty reserve adder.

How this compares with the baseline

  • Against the tool's baseline example, where expected field failure rate over warranty term sits at 3% and the headline result is 25,300 $, this scenario comes in 13.52% above the baseline at 28,720 $.
  • A figure at this level is achievable when expected field failure rate over warranty term is genuinely sustained, not just peaked for a shift. It assumes a single blended failure rate and event cost; mixed product families with very different reliability should be reserved separately and summed.

Results at a glance

  • Total warranty reserve cost: 28,720 $ (headline result)
  • Warranty reserve cost per unit: 3.59 $ / piece
  • Variable warranty reserve cost: 26,220 $
  • Fixed warranty reserve adder: 2,500 $

Run it with your numbers

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

Last reviewed 2026-05-12.