The transfer lines dealt with in this paper are equipped with multifunctional spindle heads, capable to realize several operations in the same time (in parallel) on the same work-piece. Each such multifunctional spindle head is called a block and is fully described by its set of operations, operating time and cost. The reconfigurability concerns here the possibility of realizing a family of products with the same equipment. The blocks and the product family features are supposed known. The problem is to assign the blocks to workstations such as to minimize the total cost of the line and to meet a set of time and technological constraints for the whole product family. This problem is formulated as a linear program (LP) and solved by using the Cplex ILOG optimization software. An example is provided to illustrate the steps of the proposed solving method