Comparative Analysis of Manual and Automated Welding Processes in a Steel Fabrication Workshop in Lagos State

This research compares the productivity, quality, and cost characteristics of manual Metal Inert Gas welding and automated robotic welding processes in a steel fabrication workshop in Lagos State, South West Nigeria. As Nigerian manufacturing firms consider automation investments to improve competitiveness, evidence-based comparisons of automated and manual processes in the local context are essential for informed decision-making. This study employs a mixed-methods approach, combining time study data collection, weld quality inspection using visual and non-destructive testing methods, and cost analysis. Production data were gathered over eight weeks, with equal sample sizes of one hundred weld joints evaluated for each process across three joint configurations: butt, fillet, and lap joints. Results indicate that automated welding achieves a twenty-seven percent faster deposition rate and produces significantly fewer porosity defects as measured by radiographic testing, but incurs a forty-one percent higher total cost per metre of weld at current production volumes due to equipment amortisation. Break-even analysis shows that the automated process becomes cost-competitive at production volumes exceeding three thousand metres of weld per month. Recommendations advise a phased automation strategy aligned to production volume growth projections. Keywords: welding process comparison, Metal Inert Gas welding, robotic welding, steel fabrication, Lagos State