Measurement, Test & Control Equipment worked example

Burn-In Rack Capacity at 99% chamber and rack uptime: a worked example

Push chamber and rack uptime up to 99% and the picture changes. This example computes every intermediate figure at that operating point. Use when planning burn-in capacity for new product launches, determining if you need additional burn-in racks or chambers, or scheduling burn-in slots against production demand.

The inputs for this scenario

  • Units per rack load: 48 units / cycle (unchanged)
  • Burn-in cycles per shift: 2 cycles (unchanged)
  • Chamber and rack uptime: 99 % (raised for this scenario; the documented default is 90)
  • Burn-in screening yield: 97 % (unchanged)

Working through the calculation

  • Applying the documented formula (Gross burn-in capacity = units per rack load x burn-in cycles per shift) to the inputs above produces each figure below.
  • At this operating point the engine returns 92.19 units for good units per shift (after screening), the number this scenario is built around.
  • At this operating point the engine returns 96 units for gross burn-in capacity per shift.
  • At this operating point the engine returns 0.96 units for units lost to downtime.
  • At this operating point the engine returns 2.85 units for units lost to infant mortality.

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 10% above the baseline at 92.19 units.
  • It computes gross capacity as rack load times cycles per shift, then multiplies by chamber uptime and screening yield to give good units delivered per shift. 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

  • Good units per shift (after screening): 92.19 units (headline result)
  • Gross burn-in capacity per shift: 96 units
  • Units lost to downtime: 0.96 units
  • Units lost to infant mortality: 2.85 units

Run it with your numbers

  • Every input above is editable in the live Burn-In Rack Capacity calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.