Availability assessment-simulation approach

In this paper we are interested in the assessment of the availability of a bus sample with four scheduling methods. We developed a simulation model considering a bus as an entity undergoing breakdowns due to unreliability. These breakdowns are of four types which are mechanical, electric, air conditioning, and coach-building. The assignment of a breakdown to one of the above types depends on a factor determined from the maintenance history. A preliminary study of the maintenance data shows that the occurrence of breakdowns can be modeled by, either the exponential or the Weibull distribution. As for the repair duration of all the breakdown types, they are modeled by the lognormale distribution. Results indicate that the buses availability fluctuates at the beginning of the simulation to stabilize afterward. These results are sensitive to the scheduling method.