The optimization model presented in Section 3.2 is an integer non- linear/non-smooth optimization model with non-linear constraints. Given the combination of integer constraints and a non-linear obje- ctive function, we propose a genetic algorithm (GA) to solve the problem and we use MATLAB as the mathematical programming environment. In the following sections, we present the specifics of our customized genetic algorithm. For further material on genetic algo- rithms, refer to Goldberg (1989).