The studied problem consists in designing a reconfigurable modular multi-product line that is able to handle several products. For each product, an admissible line configuration is required. Switching from one product configuration to another is performed by adding, moving, or removing modules. Hence, the optimization problem aims at finding the best configuration for each product that minimizes the total number of used modules. To do this, a new MILP formulation is proposed along with a new pattern generation algorithm.