GREY RELATIONAL ANALYSIS IN FMEA FOR GAS TURBINE RISK PRIORITIZATION

Abstract

This study proposed risk prioritization of gas turbine power plant using Grey relational analysis (GRA) 
approach. Firstly, Failure Mode and Effects Analysis (FMEA) was applied for the risk analysis of the 
system. The risk priority in the FMEA was determined using risk priority numbers (RPNs) that can be 
obtained by evaluating three factors: occurrence (O), severity (S), and detection (D). It was observed that 
the conventional FMEA based on crisp RPN is not robust enough in risk priority ranking of the failure 
modes. To overcome this short-coming we employed Grey relational analysis (GRA) to calculate the grey 
relation coefficient. The GRA method produced the following results for the first five failure modes: FM1= 
0.4337, FM2 = 0.5215, FM3 = 0.5699, FM4 = 0.5307, and FM5 = 0.6565. Unlike traditional FMEA which 
produced identical RPN values of 54 for FM3 and FM6, GRA distinguished these as 0.5699 and 0.5314 
respectively. This result shows that the GRA method was able to resolve the drawback observed in the 
traditional FMEA approach. The feasibility of GRA in FMEA was verified by using it to deal with failure 
risk evaluation of the compressor subsystem of a gas turbine power plant.