We suggest a new mathematical model for the equipment selection and the design of a transfer line intended for a mass production of machine parts of the same type. The transfer line is a sequence of (work)stations equipped with processing modules (blocks) each of which performs specific operations. Each machine part moves along the transfer line in the same direction and undergoes a given set of operations at the stations. There is the same cost associated with each station and different costs associated with the blocks. The problem is to determine the number of stations, to select a set of blocks from the set of available blocks and to assign these blocks to the stations so that each operation is performed exactly once and the total cost is minimized. The peculiarity of the problem is that all operations of the same station are performed in parallel, the assignment of the blocks and operations to a station are restricted by exclusion and inclusion relations, and the processing order of the operations on the transfer line must comply with precedence relations. We suggest a reduction of this problem to a set partitioning type problem. The reduction is based on a new concept of a locally feasible station.