Maintenance decision support: Analysing crankcase lubricant condition by Markov process modelling

The probabilistic changes in certain measurable physical parameters of a lubricant are used to develop a mathematical model of the physical-chemical deterioration process taking place in the crankcase of locomotive diesel engines. A seven-state Markov chain is formulated with actual data taken from the year 1985. Statistical inference is used to establish that the chain is of the first order and that is applicable across the fleet of locomotives in the study. The Markov model is shown to have the twin advantages of the enhancing one’s understanding of the deterioration process and of providing a means for predicting future changes. The model also lends itself to the specification of input data.