Printing, Labels & Industrial Converting worked example

Substrate Inventory Days at 99% expected press efficiency: a worked example

Push expected press efficiency up to 99% and the picture changes. This example computes every intermediate figure at that operating point. Use it when substrate inventory days in printing, labels and industrial converting is being committed and you need a throughput number you can defend.

The inputs for this scenario

  • Substrate sheets or rolls run in the shift: 1,200 units (unchanged)
  • Press run time for the shift: 8 hr (unchanged)
  • Expected press efficiency (uptime × good rate): 99 % (raised for this scenario; the documented default is 90)

Working through the calculation

  • Applying the documented formula (Substrate inventory days throughput = substrate inventory days output quantity ÷ substrate inventory days runtime) to the inputs above produces each figure below.
  • At this operating point the engine returns 149 units/hr for effective substrate inventory days throughput, the number this scenario is built around.
  • At this operating point the engine returns 150 units/hr for raw throughput.
  • At this operating point the engine returns 99 % for expected substrate inventory days efficiency.
  • At this operating point the engine returns 8 hr for substrate inventory days runtime.

How this compares with the baseline

  • Against the tool's baseline example, where expected press efficiency sits at 90% and the headline result is 135 units/hr, this scenario comes in 10% above the baseline at 149 units/hr.
  • It computes effective substrate throughput in units per hour by dividing shift output by run time and derating for real press efficiency. 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

  • Effective substrate inventory days throughput: 149 units/hr (headline result)
  • Raw throughput: 150 units/hr
  • Expected substrate inventory days efficiency: 99 %
  • Substrate inventory days runtime: 8 hr

Run it with your numbers

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

Last reviewed 2026-05-12.