Today manufacturing companies are facing a very dynamic environment, and they have to use reconfigurable manufacturing lines (RML) to stay competitive. Current production planning models oriented on dedicated manufacturing lines do not allow to produce of more than one product per line without costly changes in manufacturing and are limited in flexibility. A novel production planning model of RML is presented in this paper. This model provides a high degree of pliancy for a wide range of product types to be manufactured. The main characteristics and planning requirements for RML are defined, taking into account manufactured products, manufacturing periods, line configurations, demand scenarios, and different model parameters like production costs, reconfiguration costs, idle costs, and others. The main goal is to determine the minimum-cost configuration for a target production program. An optimal configuration of RML was determined, using mixed integer linear programming (MILP) to realize capacity scalability and functionality changes within planning processes. Finally, the model was validated in a scenario based on an industrial use case.