Maintenance priorities determination for a repairable unit of a sugar plant

Abstract

Abstract In the present study, a repairable unit of a sugar plant has been considered to determine the maintenance priorities of various subsystems of the unit. The selected repairable unit is crushing unit and it comprises of crusher, inter carrier and pump subsystems. Performance modeling of the unit is based on Markov approach. From the transition diagram of the unit, Chapman-Kolmogorov differential equations are derived. The equations are then solved to get the availability in steady state. It is assumed that all subsystems have constant rates of failure and repair. After that, development of decision matrices has been done for all subsystems. For various permutations of failure rates as well as repair rates, these decision matrices present different levels of availability for all the subsystems. On the basis of various values of availabilities and the graphs of failure and repair rates of subsystems, the optimum values of failure and repair rates are selected for maximum availability of each subsystem. Accordingly, priorities for maintenance are determined for various subsystems of repairable crushing unit. This will ensure maximum availability level of the crushing unit and will finally lead to the overall performance enhancement thereby maximizing the profitability of the plant.