Welding & Fabrication worked example

Assembly Fit-Up Time at 35% crane, jig, and squaring allowance: a worked example

Push crane, jig, and squaring allowance up to 35% and the picture changes. This example computes every intermediate figure at that operating point. Use it to plan the fitter time required to lay out, gauge, square, and clamp a weldment in the jig before tack welding starts.

The inputs for this scenario

  • Fit-up features to gauge and clamp: 18 features (unchanged)
  • Features fit per minute: 2 features / min (unchanged)
  • Crane, jig, and squaring allowance: 35 % (raised for this scenario; the documented default is 30)

Working through the calculation

  • Applying the documented formula (Base assembly fit-up time = fit-up features to gauge and clamp รท features fit per minute) to the inputs above produces each figure below.
  • At this operating point the engine returns 12.15 min for required assembly fit-up time, the number this scenario is built around.
  • At this operating point the engine returns 9 min for base assembly fit-up time.
  • At this operating point the engine returns 35 % for crane, jig, and squaring allowance.
  • At this operating point the engine returns 2 pieces / min for features fit per minute.

How this compares with the baseline

  • Against the tool's baseline example, where crane, jig, and squaring allowance sits at 30% and the headline result is 11.7 min, this scenario comes in 3.85% above the baseline at 12.15 min.
  • It divides the number of fit-up features by the fit rate to get base minutes, then inflates that by a crane, jig, and squaring allowance. 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

  • Required assembly fit-up time: 12.15 min (headline result)
  • Base assembly fit-up time: 9 min
  • Crane, jig, and squaring allowance: 35 %
  • Features fit per minute: 2 pieces / min

Run it with your numbers

  • Every input above is editable in the live Assembly Fit-Up Time calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.