Leone, Ann Marie (1987, ASQC) Westinghouse Electric Corporation, Baltimore, MD
The author has developed an industry generic application of the Department of Army Reliability Centered Maintenance concepts.1 This application is geared towards almost any facility in which safety or function of a large system is critically dependent on cost effective preventive maintenance schedules, and is espeically useful to aerospace and transportation industries. This application combines and automates the tasks of reliability centered maintenance which are generally tedious and require large amount of paperwork. It eliminates redundant input of information from one task to another.The application consists of four dependent modules which are linked by the appropriate database management system and software tools. (There are many tools available such as electronic spreadsheet, fifth generation database management systems, graphics, etc.) The four modules are: Failure Modes Effects and Criticality Analysis module, and Optimal Preventive Scheduling module.The application assumes that the parts information has already been entered into the database. All of the necessary inputs such as failure rate and unit replacement costs must also be entered. The modules are arranged so that once the user inputs the information, it never has to be reentered again.The Failure Modes Effects and Criticality Analysis (FMECA) is the first step in determining a RCM schedule. A FMECA is prepared for each replaceable unit. The viewpoint of the FMECA can either be safety or functional criticality to the system and subsystems. Once the user has performed the FMECA, the outputs of the FMECA are used to perform the Logistics Support Analysis (LSA)2 algorithm.The LSA algorithm determines the component to be either critical or non-critical to the system. Reliability and maintenance characteristics of the unit are input. From these inputs the algorithm determines the possible preventive maintenance plans which could be implemented for this particular unit. There are three possible preventive maintenance types. They are hard time replacement, on-condition maintenance, and condition monitoring.The third module of the application is the cost analysis. The applicable preventive maintenance options determined for each unit by the LSA algorithm are analyzed for cost effectiveness. If there is more than one option for a particular unit, the options are compared and the optimal solution determined. The cost of preventive maintenance and the maintenance intervals are determined.Finally, the application implements the results of the cost analysis to project a complete sytem schedule. This schedule most effectively and efficiently combines the maintenance tasks into an overall schedule. The manpower required for the maintenance can be easily determined by the schedule.
Aerospace industry,Department of Defense (DOD)