Eyewear, Lenses & Vision Products worked example

Custom Order Lead Time with custom orders in backlog of 1,100 orders: a worked example in eyewear, lenses & vision products

This scenario runs the custom order lead time calculation on the strong side: custom orders in backlog of 1,100 orders, with every other input held at its documented default. an operations manager needs to set realistic lead-time promises for custom eyewear orders

The inputs for this scenario

  • Custom orders in backlog: 1,100 orders (raised for this scenario; the documented default is 420)
  • Completed custom orders per day: 70 orders / day (unchanged)
  • Active custom-order workstreams: 2 workstreams (unchanged)

Working through the calculation

  • Applying the documented formula (Single-workstream queue days = custom orders in backlog รท completed custom orders per day) to the inputs above produces each figure below.
  • At this operating point the engine returns 7.86 days for estimated custom order lead time, the number this scenario is built around.
  • At this operating point the engine returns 15.71 days for single-workstream queue days.
  • At this operating point the engine returns 1,100 orders for custom orders in backlog.
  • At this operating point the engine returns 70 orders / day for completed custom orders per day.

How this compares with the baseline

  • Against the tool's baseline example, where custom orders in backlog sits at 420 orders and the headline result is 3 days, this scenario comes in 162% above the baseline at 7.86 days.
  • Use it when quoting a turnaround to a customer, deciding whether to add a workstream, or checking whether the backlog is growing faster than you can clear it. Treat this as a target state: the delta against the baseline quantifies what the improvement is worth before you commit to chasing it.

Results at a glance

  • Estimated custom order lead time: 7.86 days (headline result)
  • Single-workstream queue days: 15.71 days
  • Custom orders in backlog: 1,100 orders
  • Completed custom orders per day: 70 orders / day

Run it with your numbers

  • Every input above is editable in the live Custom Order Lead Time calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.