Desalination & Membrane Water Treatment Equipment worked example

Membrane Skid Assembly Labor at 7.2% fit-up, test, and rework allowance: a worked example

Suppose fit-up, test, and rework allowance falls to 7.2%. This page works the full calculation at that level so you can see exactly which result moves and by how much. Estimate fabrication and assembly labor for RO, UF, NF, or MF skids including pressure vessels, pumps, piping, valves, instruments, controls, and factory checks.

The inputs for this scenario

  • Skid assembly work packages: 120 packages (held at the documented default)
  • Assembly completion pace: 12 packages / hr (held at the documented default)
  • Fit-up, test, and rework allowance: 7.2 % (the input this scenario stresses; the baseline uses 10)

Working through the calculation

  • The calculation starts from the formula this tool documents: Base skid assembly hours = skid assembly work packages รท assembly completion pace.
  • Required skid assembly labor hours works out to 10.72 hr at these inputs, and this is the headline figure for the scenario.
  • Base skid assembly hours works out to 10 hr at these inputs.
  • Fit-up, test, and rework allowance works out to 7.2 % at these inputs.
  • Assembly completion pace works out to 12 pieces / min at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where fit-up, test, and rework allowance sits at 10% and the headline result is 11 hr, this scenario comes in 2.55% below the baseline at 10.72 hr.
  • It computes the labor hours to assemble a membrane skid from its work-package count, scaled by an allowance for fit-up, testing, and rework. 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

  • Required skid assembly labor hours: 10.72 hr (headline result)
  • Base skid assembly hours: 10 hr
  • Fit-up, test, and rework allowance: 7.2 %
  • Assembly completion pace: 12 pieces / min

Run it with your numbers

  • To rerun this with your own numbers, open the live Membrane Skid Assembly Labor calculator, set fit-up, test, and rework allowance to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.