هزینه های چرخه عمر برای پایش وضعیت راه آهن

The European Commission has estimated that by 2020 passenger traffic will double and freight traffic will triple compared with current volumes. Over the same period a reduction of 30% in the life cycle costs (LCC) of trackside assets is desired. Remote condition monitoring (RCM) can help to achieve increases in Reliability, Availability, Maintainability and Safety (RAMS) of trackside assets such as points (switches) and level crossings. Nonetheless, the application of a LCC model to RCM has hitherto been overlooked. Using a real case study, the objective of this paper is to illustrate how the cost–benefit of RCM can be evaluated.

Condition monitoring has been attracting researchers in recent years and its implementations on critical systems such as nuclear power plants, military systems, airplanes, etc. has been studied extensively (Baruah and Chinnam, 2005, Ocak et al., 2007, Roemer and Kacprzynski, 2000 and Camci, 2005). Applications of condition monitoring (also called remote condition monitoring) on railway systems has been started to be seen in the literature (Roberts et al., 2002, Marqueza et al., 2003, Marqueza and Schmidb, 2007a, Marquez et al., 2007b and Marquez et al., 2007c). Identification of the value to be obtained when condition monitoring is applied on a given system has critical importance. Marquez et al. presented life cycle cost calculation method for railway condition monitoring (Marquez et al., 2008) in order to be able to identify its value. The purpose of this paper is to clarify some of the equations in Marquez et al. (2008), correct one formula and its definition. I believe that this paper will make the mathematical base of (Marquez et al., 2008) stronger.

In this paper, the calculation of savings in penalty cost is updated. One of the term used in the savings in penalty cost, which is defined as combined efficiency (η) in Marquez et al. (2008), is redefined as the probability of detecting the failure and repairing on time. In addition, the definition of P(D), which is used for calculation of combined efficiency, is redefined as probability of overall failure given that the failures are detectable. Finally, the formula of P(D) as is re-written as in Eq. (9).