The present paper proposes the development of a virtual model simulating an assembly line. Starting from the analysis of the real line, through an incremental approach, a simulation model is created, verified and validated, in order to obtain useful information about: • productive capacity; • partial and total lead time; • Percentage of saturation, Value Added (VA) and Non-Value Added (NVA), for each worker and station. During the development phase, an important goal has been pursued: the possibility to use and change the model without knowing the creation logic. It is possible to change input parameters through simple tables, which contain times of man-machine operations. You can easily set times in order to move an operation from one station to another or to add/delete a job in a station, according to the technological and ergonomic constraints of the process. Moreover, the acquisition of scheduling data is extremely easy and starts from the generation of a list of production codes related to different work-cycles.