Measurement, Test & Control Equipment worked example

Burn-In Rack Capacity at 65% chamber and rack uptime: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop chamber and rack uptime to 65%, then walk the calculation through step by step. Calculate the effective throughput capacity of your burn-in racks per shift, accounting for rack slot count, burn-in cycle duration, equipment uptime, and infant mortality screening yield.

The inputs for this scenario

  • Units per rack load: 48 units / cycle (held at the documented default)
  • Burn-in cycles per shift: 2 cycles (held at the documented default)
  • Chamber and rack uptime: 65 % (the input this scenario stresses; the baseline uses 90)
  • Burn-in screening yield: 97 % (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Gross burn-in capacity = units per rack load x burn-in cycles per shift.
  • Good units per shift (after screening) works out to 60.53 units at these inputs, and this is the headline figure for the scenario.
  • Gross burn-in capacity per shift works out to 96 units at these inputs.
  • Units lost to downtime works out to 33.6 units at these inputs.
  • Units lost to infant mortality works out to 1.87 units at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where chamber and rack uptime sits at 90% and the headline result is 83.81 units, this scenario comes in 27.78% below the baseline at 60.53 units.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to chamber and rack uptime, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It assumes uptime and yield are stable averages; a chamber failure mid-shift or a yield excursion from a bad lot will produce far fewer good units than the steady-state estimate.

Results at a glance

  • Good units per shift (after screening): 60.53 units (headline result)
  • Gross burn-in capacity per shift: 96 units
  • Units lost to downtime: 33.6 units
  • Units lost to infant mortality: 1.87 units

Run it with your numbers

  • To rerun this with your own numbers, open the live Burn-In Rack Capacity calculator, set chamber and rack uptime to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.