Workshop Fabrication

Fabrication Man-hours

1. Fabrication man-hours are determined by the quantity of hours/tasks in each steel assembly, for example, each column, beam, brace, assembly, or bracket.
2. The average constants are for high repetition portal frame and high rise type work. The ranges are for differences in piece size, detail, repetition, and fabrication methods.
3. These constants are based on conventional fabrication methods used by most fabricators, ie manual gas cutting and magnetic broach drilling, and semi-automatic “mig” or “flux core” welding.
4. With semi-automated saw and drill lines output is much higher but machine costs are higher, and generally the market does not differentiate costs because semi-automation affects only part of overall fabrication.
5. The constants include for reading fabrication drawings, stacking and sorting materials, marking out, turning, grinding edges and welds, operator setting up, servicing gear such as welders and grinders, and QA including average rework.
6. These constants are “whole of job”, and hence will differ from spot check times which will not be representative of a complete job due to the tendancy not to include downtime and variances in productivity.
7. Repetition affects productivity in different ways, and for some labour operations can have a significant impact on output, while other labours produce only slight improvements. A high degree of difficulty can also have a large impact on output, for example, very detailed drawings, angled assembly, low repetition of detail, complex set out.