Welding jig design is a specialized technique aimed at stabilizing welding quality and improving productivity by precisely fixing the workpiece (object to be welded) in position and suppressing deformation caused by welding heat during welding operations. The design process comprehensively considers high-precision positioning and clamping mechanisms, accessibility for the welding torch, spatter countermeasures, and worker safety and operability. Particularly, it is crucial to predict shrinkage and distortion of the workpiece due to heat effects and design to offset them. It is indispensable in a wide range of manufacturing industries, including automobiles, construction machinery, and industrial machinery, and significantly contributes to reducing setup time, lowering defect rates, and standardizing quality.