DEVELOPMENT OF A CRITICALITY INDEX FOR PREVENTIVE MAINTENANCE PROGRAMME

摘要

This work analyses and describes the relevant steps for the development of a preventive maintenance programme for an oil refinery plant located in Falconara (Italy). The actual oil company maintenance policy is essentially a corrective type one (based on failures), with ordinary and extraordinary repairs for the most of the process plants items. The preventive maintenance programme for the most critical equipments of the reference plant is developed analysing the used oil sector standards (ASA, API, UNI, ISO, ASME). These standards have been used for several oil refinery equipments such as pumps, tanks and processing furnaces. The relevant technical specifications (operating conditions, process fluids and safety system configuration) have been gathered for each component. The data have then been used to assess the failure mode effects and severity so that to calculate the criticality index. The outcome of the analysis has highlighted important relations among variable, confirming and validating the results obtained through other reliability assessment techniques (see Bevilacqua et al. [1]). This paper reports the application of the Criticality Index method to two specific stages in the maintenance activities of the refinery, i.e. the oil refinery turnaround and work orders management. The results have highlighted a clear improvement in the indices which measure the quality of maintenance.