This research is carried out to improve productivity of robot welding shop in subassembly line. This is a part of full automation of robot welding shop and it is realized as the 3D simulator for robot welding. UML and IDEF methods are used to analyze system to be model and the analysis is to be the foundation of simulator. Robot welding shop is a semi-mechanized shop. So this shop has possibility to be mechanization and it can be simulated precisely than other shop operated by a worker.
But there are some problems to be considered. It is caused by many machines, non-fixed materials. The problems are determination of working sequence and work area and these need other optimum techniques. The concept of TSP and genetic algorithm are used to find shortest work sequence. Simulator for robot welding shop is implemented to verify the result of optimum plans and to estimates cycle time for specific amount of work be done.