Studying periodic maintenance programs, failures and their sources for agricultural tractors, Ceylanpınar agricultural enterprise a case of study

This study depended on examining kept periodic records of maintenance and repair costs collected over ten years of continuous working of 11 Valtra 8400-2003 tractors in Agricultural Enterprise of Ceylanpinar. The data of observed failures and repair and maintenance costs were obtained and repair and maintenance costs were analyzed mathematically. In order to predict the accumulated repair and maintenance costs precisely, mathematical models were developed by studying their relations with the accumulated working hours of tractor which were adopted as an independent variable in four different values. Furthermore, the developed models were compared with other similar ones developed in other countries of the world. Depending on the results of this comparison and taking tractor working conditions into consideration, a group of mathematical models were suggested in order to develop the accumulated repair and maintenance costs. Moreover, the total observed failures and failure rates were analyzed mathematically. Finally, the relation between of the failure rates of tractors and the accumulated repair and maintenance costs and the accumulated working hours was determined.