How do you calculate field install savings throughput?

Divide modules completed by assembly hours for raw throughput, then multiply by efficiency. With 1200 modules over 8 hours at 90%, raw is 150/hr and effective is 135/hr.

Why apply an efficiency factor to shop throughput?

Raw throughput assumes perfect flow. Applying 90% efficiency accounts for setup, rework, and fit-up delays, dropping the 150/hr raw figure to a realistic 135/hr.

What is a good shop build efficiency?

Mature skid shops run 85-92% on repeat work. The 90% default is a solid steady-state assumption; first-of-a-kind modules often start in the 70s until the crew learns the build.

Modularization vs field stick-build, which wins?

Shop fabrication typically saves 25-40% on install labor because effective throughput like 135/hr is unattainable in field conditions with weather, permits, and congestion.

Does higher throughput always mean lower cost?

Not if efficiency is bought by skipping QA. A 150/hr raw rate that generates field rework can cost more than a steady 135/hr effective rate with clean handover.

How do I raise effective throughput?

Close the gap between raw and effective by attacking the efficiency loss: standardize fit-up jigs, sequence trades, and cut wait time so more of the 8 hours is value-added.

Process Skids, Modular Equipment & Packaged Plants calculator

Field Install Savings Calculator

Field Install Savings quantifies how much work your shop absorbs per assembly hour so you can compare shop-fabricated modularization against stick-building in the field. Estimators and modularization leads on packaged-plant projects use it to defend the premise that controlled shop conditions beat field labor. Every module completed in the shop is welding, wiring, and testing that never happens on a muddy, weather-exposed site at field labor rates. By translating output and hours into an efficiency-adjusted throughput, the tool gives a defensible number for bids and for post-project lessons learned.

What this calculator does

Field Install Savings quantifies how much work your shop absorbs per assembly hour so you can compare shop-fabricated modularization against stick-building in the field.
Use it when field install savings in process skids, modular equipment and packaged plants is being committed and you need a throughput number you can defend.
It computes throughput as modules per assembly hour, then discounts it by shop efficiency to give a realistic effective rate.

Formula used

Raw field install savings = completed output ÷ runtime
Effective field install savings = raw throughput × efficiency

Inputs explained

Modules shop-fabricated:
Assembly hours consumed:
Shop build efficiency:

How to use the result

Use it when building a modularization business case or benchmarking one shop build against another.
It treats every module as equivalent; a complex pump skid and a simple pipe rack both count as one unit unless you normalize them.

Current U.S. benchmarks

Steel mill PPI stands at 348.53 (BLS, May 2026), up 6.7% from a year earlier. New factory orders are up 2.3% year over year (Census).

Common questions

How do you calculate field install savings throughput? Divide modules completed by assembly hours for raw throughput, then multiply by efficiency. With 1200 modules over 8 hours at 90%, raw is 150/hr and effective is 135/hr.
Why apply an efficiency factor to shop throughput? Raw throughput assumes perfect flow. Applying 90% efficiency accounts for setup, rework, and fit-up delays, dropping the 150/hr raw figure to a realistic 135/hr.
What is a good shop build efficiency? Mature skid shops run 85-92% on repeat work. The 90% default is a solid steady-state assumption; first-of-a-kind modules often start in the 70s until the crew learns the build.
Modularization vs field stick-build, which wins? Shop fabrication typically saves 25-40% on install labor because effective throughput like 135/hr is unattainable in field conditions with weather, permits, and congestion.
Does higher throughput always mean lower cost? Not if efficiency is bought by skipping QA. A 150/hr raw rate that generates field rework can cost more than a steady 135/hr effective rate with clean handover.

Last reviewed 2026-05-12.