Quantifying the added value of an imperfectly performing condition monitoring system–Application to a wind turbine gearbox

Implementation of a condition monitoring system is a difficult decision due to many uncertain parameters. This is certainly the case for the wind turbine industry where factors like long logistical times and weather conditions have a major influence on the economic benefit. One of the parameters that is neglected in most of the available literature is the performance of the condition monitoring system itself. In this paper a new concept for modeling this performance based on the P–F curve of different failure modes is presented. The concept is illustrated on an extensive case study for a gearbox of a wind turbine. A stochastic simulation model is constructed in order to quantify the economic added value of implementing an imperfectly performing condition monitoring system into a gearbox. This case study proves that a condition monitoring system generates an economic benefit compared to the currently applied maintenance strategy. However, the magnitude of this benefit depends strongly on the performance of the condition monitoring system.