Printing, Labels & Industrial Converting worked example

Substrate Inventory Days at 65% expected press efficiency: a worked example

Suppose expected press efficiency falls to 65%. This page works the full calculation at that level so you can see exactly which result moves and by how much. Estimate substrate inventory days for printing, labels and industrial converting using production-ready inputs so teams can measure output per hour and compare it with the required production pace.

The inputs for this scenario

  • Substrate sheets or rolls run in the shift: 1,200 units (held at the documented default)
  • Press run time for the shift: 8 hr (held at the documented default)
  • Expected press efficiency (uptime × good rate): 65 % (the input this scenario stresses; the baseline uses 90)

Working through the calculation

  • The calculation starts from the formula this tool documents: Substrate inventory days throughput = substrate inventory days output quantity ÷ substrate inventory days runtime.
  • Effective substrate inventory days throughput works out to 97.5 units/hr at these inputs, and this is the headline figure for the scenario.
  • Raw throughput works out to 150 units/hr at these inputs.
  • Expected substrate inventory days efficiency works out to 65 % at these inputs.
  • Substrate inventory days runtime works out to 8 hr at these inputs.

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 27.78% below the baseline at 97.5 units/hr.
  • It computes effective substrate throughput in units per hour by dividing shift output by run time and derating for real press efficiency. When the numbers land here, the stressed input is the lever to work; the walkthrough above shows exactly how much each output recovers as it climbs back toward the baseline.

Results at a glance

  • Effective substrate inventory days throughput: 97.5 units/hr (headline result)
  • Raw throughput: 150 units/hr
  • Expected substrate inventory days efficiency: 65 %
  • Substrate inventory days runtime: 8 hr

Run it with your numbers

  • To rerun this with your own numbers, open the live Substrate Inventory Days calculator, set expected press efficiency to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.