This paper presents the operator's point of work for spot welding of the vehicle body and a range of challenges and problems occurring in welding, even if the welding process is carried out by robot, thereby reducing the impact of human factors. The advantages and disadvantages of robot welding, as well as the parameters used to select robots in the job, are listed. Precise instructions have been given how the worker deals in dangerous situations, and ways to avoid it completely. The key optimal organization and structure of the workplace, the position of the worker - operator and his role in relation to the machine is presented. The standards of assembly and moving of facilities within the factory are specified. Problems with the monotonous work of the workers and the prevention of error reporting have been noted using certain sensors and quality control. This paper presents all influential sizes and guides whose optimization achieves the desired improvements in man and machine, taking into account the quality assurance and performance of work tasks. Numerous efforts are made in the performance of the work and the consequences that arise as a result of the effort. An analysis of the effort in manual and robot welding was carried out under the Renault standard. Evaluated and commented are the results obtained and the ways of improving and optimizing them. From the practice, examples of constructions are given together with a look at the most important ergonomic features that are essential for the work of the workers. In the conclusion most important features of the work were commented and guidelines were given how we should approach ergonomic type problems in the future.