Abstract: This study describes the formulation of a general model for the decision support needs of maintenance and production managers while deciding upon machine replacement policies. The study also focused in the applicability of genetic algorithms to solve replacement models. A genetic algorithm based Decision Support System (DSS) was successfully developed to cope with such needs. The computer system replaces the intuitive, non-quantifiable, error-prone and time-consuming calculations currently employed by managers, by a more systematic and consistent approach to decision-making.