Lighting, LEDs & Electrical Fixtures worked example

Driver Failure Cost at 1.73% expected driver failure rate: a worked example

This scenario runs the driver failure cost calculation on the strong side: 1.73% expected driver failure rate, with every other input held at its documented default. Use this when sizing warranty reserves, evaluating a driver supplier change, comparing self-contained vs. remote driver designs, or preparing a quality cost report for a product launch.

The inputs for this scenario

  • Fixtures under warranty: 5,000 fixtures (unchanged)
  • Driver replacement cost per failure: 75 $ / failure (unchanged)
  • Expected driver failure rate: 1.73 % (raised for this scenario; the documented default is 1.5)
  • Fixed warranty administration cost: 800 $ (unchanged)

Working through the calculation

  • Applying the documented formula (Variable warranty cost = fixtures under warranty x replacement cost per failure x expected failure rate%) to the inputs above produces each figure below.
  • At this operating point the engine returns 7,288 $ for total driver failure warranty cost, the number this scenario is built around.
  • At this operating point the engine returns 1.46 $ / piece for cost per failed driver.
  • At this operating point the engine returns 6,488 $ for variable warranty cost.
  • At this operating point the engine returns 800 $ for fixed warranty admin cost.

How this compares with the baseline

  • Against the tool's baseline example, where expected driver failure rate sits at 1.5% and the headline result is 6,425 $, this scenario comes in 13.42% above the baseline at 7,288 $.
  • Use it when setting warranty reserves, pricing a 5- or 10-year driver warranty, or comparing the lifetime cost of two driver suppliers with different failure rates. Treat this as a target state: the delta against the baseline quantifies what the improvement is worth before you commit to chasing it.

Results at a glance

  • Total driver failure warranty cost: 7,288 $ (headline result)
  • Cost per failed driver: 1.46 $ / piece
  • Variable warranty cost: 6,488 $
  • Fixed warranty admin cost: 800 $

Run it with your numbers

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

Last reviewed 2026-05-12.