Reliability centered maintenance and risk assessment

The authors found weaknesses in traditional Reliability Centered Maintenance (RCM) methods when applied to Space Shuttle Program maintenance activities. The first difficulty involved the standard RCM treatment of safety risk as a yes/no question. The Shuttle Program personnel performing RCM might not answer the question consistently; many situations may not be so black-and-white. Second, the Shuttle Program recognized many other areas of risk (mission success, launch manifest, etc.) that the safety question did not address. These other types of risk often defied economic analysis, as did the safety risk, leaving a disturbing gap in traditional RCM approaches in this application. The authors incorporated a risk assessment tool into the RCM approach to handle these weaknesses. This tool addressed five categories of risk: safety, mission success, schedule, supportability, and cost. The tool also provided a means of quantifying both the severity and probability of the risk. In addition to other modifications to the traditional RCM methodology, the new "streamlined" RCM approach provided a successful maintenance analysis tool for Shuttle ground support equipment and facilities.