This paper describes the development of a simulation model. The model deals with the role of assembly worker in the virtual environment with an emphasis on ergonomics and time analysis. Firstly, we analyse time reports of common tasks in manufacturing processes like reaching, lifting etc. We receive time reports from three different methods: analytical MTM method, Siemens JACK 8.4 simulation and practical experiment. Secondly, we look into influential parameters, dimensions and mass of object, which affect the time reports. The results of our research show us that the parameters have different weight of importance. The main goal of this paper is to propose suggestions and guidelines for a worker-friendly environment from an automated generated ergonomic report of JACK simulation. We also ergonomically evaluate the task of lifting with the NIOSH method and propose improvements.