HVAC Ductwork, Air Handling & Mechanical Products worked example

Flange Count at 66% roll-forming line uptime: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop roll-forming line uptime to 66%, then walk the calculation through step by step. Estimate total duct flange and connection production output per shift. Combine flanges per setup, available setups per shift, TDC or TDF roll-forming line uptime, and first-pass yield to plan flange inventory and assembly scheduling.

The inputs for this scenario

  • Flange sets produced per roll-forming setup: 6 sets / setup (held at the documented default)
  • Available roll-forming setups per shift: 80 setups (held at the documented default)
  • Roll-forming line uptime: 66 % (the input this scenario stresses; the baseline uses 92)
  • First-pass flange dimensional yield: 97 % (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Gross flange output = flange sets per setup × available setups.
  • Good output capacity works out to 307 units at these inputs, and this is the headline figure for the scenario.
  • Gross capacity works out to 480 units at these inputs.
  • Uptime loss works out to 163 units at these inputs.
  • Yield loss works out to 9.5 units at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where roll-forming line uptime sits at 92% and the headline result is 428 units, this scenario comes in 28.26% below the baseline at 307 units.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to roll-forming line uptime, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It assumes a steady-state shift; major coil changeovers, die swaps for a different flange profile, or a corner-piece shortage can drop real output below the calculated count.

Results at a glance

  • Good output capacity: 307 units (headline result)
  • Gross capacity: 480 units
  • Uptime loss: 163 units
  • Yield loss: 9.5 units

Run it with your numbers

  • To rerun this with your own numbers, open the live Flange Count calculator, set roll-forming line uptime to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.