SENSITIVITY ANALYSIS OF RELIABILITY INDEXES WITH RESPECT TO EQUIPMENTFAILURE AND REPAIR RATES

This paper describes a methodology for calculating the sensitivity of reliability indices such as LOLP, EPNS and LOLF with respect to variat ions in equipment failure and repair rates. This information can be us ed to assess the cost/benefit of improving equipment reliability, eith er reducing downtime by hiring additional personnel for repairs or ext ending uptime through more sophisticated monitoring and maintenance te chniques. The sensitivity indices can also be used to estimate the imp act of parameter uncertainty on reliability indices. The methodology i s easy to implement on existing reliability evaluation programs, eithe r based on state enumeration or Monte Carlo simulation, and does not r equire additional computational effort. Case studies with the 24-bus I EEE RTS and the 1400-bus Brazilian Southeastern system are presented a nd discussed.