Abstract:

In today’s competitive world, the need to maximum utilization of available machines/equipments became more important due to the goal of achieving as possible as lowest production cost. In this scope, the analysis of availability, reliability and maintainability became essential tools in order to reach at this goal. In this study, reliability, maintainability and availability calculations were accomplished for four CNC machines used in the factory of tractor cabins. At the statistical analysis stage, failure and repair data were examined to find the suitable probability distributions (exponential, lognormal, normal, weibull). Reliability and maintainability functions for each CNC machine were then obtained based on the best fitted probability distribution. Finally, availability values were calculated and machines were compared based on these three criteria. According to results of analysis, failure and repair data best fits to Weibull and Lognormal distributions respectively. Based on these distributions, CNC-3 was found as having best operation characteristics among the CNC machines in terms of reliability and maintainability. Besides, all of the CNC machines have availability values over 99%.

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