Using anecdotal information to model the availability of an existing dynamometer system

Low-volume, custom-built or specialty equipment, by nature, has little statistically significant data to predict system availability over the equipment life. Their unique constructions are often costly to purchase and install, and are equally costly to maintain. This paper presents a practical method to estimate the availability of custom-built equipment, using a custom 4wd NVH dynamometer system as an example. The proposed method models the availability of an existing custom-built system using anecdotal component information based on interviews with field service personnel. The interview data is used to create estimated probability density functions for the major components of the system. Component probability density functions are assembled into a system model based on a derived system reliability function. This technique provides a low-cost, quick, model of system availability over time which can be used to assess the risk and cost effectiveness of system maintenance strategies.