Arc-On Time (Operating Factor)
This is the ratio of time the welding arc is actually active at the workstation to the total cycle time or working shift. It is the most straightforward indicator of our resource utilization.
The arc-on time factor (often called the operating factor) is calculated by dividing the total active arc time by the total process time, typically expressed as a percentage. The remainder of the process consists of auxiliary tasks: joint preparation, fit-up/setup, cleaning, spatter and/or slag removal, filler metal replacement, inspection, and repairs. Typical operating factors range from just a few percent in manual welding to over 90% in robotic applications.
A process engineer measures arc-on time using the built-in counter on the welding power source or via a simple stopwatch time study. This result also exposes non-productive time: if a welder or operator spends significant time on addtional activties, the root cause of the inefficiency likely lies outside the actual welding process itself.
Increasing the operating factor from 25% to 50% allows you to achieve the exact same throughput with a single workstation or operator instead of two, driving significant savings in labor costs. Before increasing headcount or investing in new equipment, the entire workflow must be optimized to maximize effective welding time.
Process audit, calculating the total cost of welding, and evaluating the business case for mechanization or automation. It involves assessing joint preparation, additional operations, changeover/setup times, and related activities.
