Maintenance is a process that makes a high-level contribution to the sustainability goal of the manufacturing facilities defined as uninterrupted, high-quality level, economic, efficient, reliable and environmentally friendly production. The foremost stage of this important process is the maintenance planning and the first and indispensable phase of this stage is the maintenance strategy selection. When considering the maintenance processes which cause the significant costs due to production downtime, material, time and labor requirements, assignment of the suitable maintenance strategies especially for the critical equipment has great importance in terms of avoiding the unnecessary costs for the generation facility. Furthermore, maintenance strategy optimization directly effects the goal of sustainable production in the manufacturing facilities by providing to increase the faultless operating time of equipment and contribute to realize the reliable and high-quality manufacturing. In addition to these, this problem becomes more and more important in the electricity generation plants which are in the group of continuous production facilities, when the effects of energy on the society are considered. In this context in this study, among the electrical equipment which are the most problematic group, the most critical ones in terms of the power plant are determined by the AHP-TOPSIS combination in one of the bigscale hydroelectric power plants realize the 20% of Turkey’s electricity generation. Then, the most appropriate strategy combination from corrective, periodic, predictive and revision maintenance strategies is obtained by using the proposed integer programming model for these equipment groups. The use of this combination has resulted in an 80% improvement in generation downtimes and associated costs