PREVENTIVE MAINTENANCE SCHEDULING ALGORITHM FOR MULTI-UNIT MULTI-STATE SYSTEM WITH APPLICATION TO A POWER STATION

Abstract

Maintenance scheduling in industry is a crucial activity where a good maintenance schedule may lead to proper system utilization and reliability. This schedule may be formulated and solved as an optimization problem where level, and time interval between different types of maintenance are the decision variables, the total cost is the objective function to be minimized, and the resources, measures of system reliability, availability, and other considerations are the constraints. In this study, a maintenance schedule optimization model is developed for multi-unit, multi­ state systems with multi-level of preventive maintenance actions or activities. The decision variable in this model is the sequence of preventive maintenance actions applied to the system in a finite time horizon. The total maintenance cost includes preventive maintenance, minimal repair, and downtime costs. Moreover, the developed model includes three types of constraints, which are system reliability, minimum interval between maintenance activities and crew availability. The proposed model is solved using simulation technique combined with a specialized• constrained genetic algorithm technique, and are programmed using MATLAB. The presented

approach has the potential to solve realistic scale problems.