Eyewear, Lenses & Vision Products worked example

Prescription Order Takt with net available production time of 230 min / shift: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop net available production time to 230 min / shift, then walk the calculation through step by step. Find the takt time for Eyewear, Lenses & Vision Products — the pace, in seconds per unit, that production must hold to exactly meet customer demand.

The inputs for this scenario

  • Net available production time: 230 min / shift (the input this scenario stresses; the baseline uses 450)
  • Customer demand: 60 units / shift (held at the documented default)
  • Shifts per day: 2 shifts (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Takt time = net available production time × 60 ÷ customer demand.
  • Takt time works out to 230 sec / unit at these inputs, and this is the headline figure for the scenario.
  • Required rate works out to 15.65 units / hr at these inputs.
  • Available time / day works out to 460 min at these inputs.
  • Demand / day works out to 120 units at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where net available production time sits at 450 min / shift and the headline result is 450 sec / unit, this scenario comes in 48.89% below the baseline at 230 sec / unit.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to net available production time, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. Takt is a demand-pace target, not actual capacity. It ignores changeovers, breaks, and yield loss, so cycle time at each station must be checked against takt with those losses already netted out of available time.

Results at a glance

  • Takt time: 230 sec / unit (headline result)
  • Required rate: 15.65 units / hr
  • Available time / day: 460 min
  • Demand / day: 120 units

Run it with your numbers

  • To rerun this with your own numbers, open the live Prescription Order Takt calculator, set net available production time to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.