Optimal product-mix means to determine the quantity of products to produce to maximize the gain. To determine the optimal product-mix of the Cooperativa Industrial Manufacturas del Centro from Huancayo city, the most important textile company in the region Andrés A. Cáceres, it has been built a hybrid model combining the discrete-event simulation and the genetic algorithms. The discrete-event simulation is used to infer the indirect unitary cost of each product due to the use of a system activity-based costing. To apply a system activity-based costing the posteriori information is required to, but one can know it (to approach it) a priori applying the discrete-event simulation. The genetic algorithms determine the optimal product-mix that maximizes the utility. These genetic algorithms use the code of value for the chromosomes and they include techniques for the solution of problems wi...