The aim of the present work is the application of simulation techniques to the project of the handling system of a semiautomatic line for the assembly of electrical switches. In particular, we have studied an Automatic Guided Vehicle (AGV) transport system. The maximum assembly capacity is 48 units per hour: - Switches single-pole: 25%, 12 units; - Switches 2 poles: 25%, 12 units; - Switches 3 poles: 50%, 24 units. A main line has been designed in order to connect the following stations: • An input station for the loading of components for the assembly of each kind of product; • Two machines for the preparation of subgroups; • A machine characterized by two stations: assembling and testing of all products (physical, electrical and magnetic); • Two final warehouses; one of finished products and another of products sent back to the testing station by an operator (inspector), through an handling system. We have a worker in each working centre.