Optimal grouping and scheduling of preventive maintenance activities

Reliability Centered Maintenance (RCM) is a well-known methodology for the optimized design of the maintenance plans in industry, whose fundamental elements are the functional analysis of the systems and their reliability quantification. From its application, a list of maintenance activities of different type is obtained (e.g., preventive or corrective), also with recommendations for the time at which the activities should be executed. Subsequently, this information is passed to management for the planning of the maintenance equipment, scheduling and for grouping the activities in feasible packages. The grouping must seek simultaneous performing opportunism, so that, the window of the time requested to the production area (equipment possession planning) as many activities as possible are executed. Several researchers have studied this problem and proposed optimization models. However, due to the complexity of the interactions of the activities and the planning horizon, it has been necessary to introduce simplification criteria. Typically, the studies focus on determining the optimal maintenance plan, seeking to minimize total maintenance costs with respect to the desired level of reliability in a multicomponent/equipment system. This paper presents an optimization model that seeks to schedule and group a plan of preventive maintenance activities for a single machine, minimizing its unavailability and respecting tolerance criteria in the periodicity of execution (advance or delay). The proposed model is continuous and solved within the mixed-integer linear programming paradigm.