TY - JFULL AU - Fatemeh Afsharnia and Mohammad Amin Asoodar and Abbas Abdeshahi PY - 2014/4/ TI - The Effect of Failure Rate on Repair and Maintenance Costs of Four Agricultural Tractor Models T2 - International Journal of Agricultural and Biosystems Engineering SP - 285 EP - 290 VL - 8 SN - 1307-6892 UR - https://publications.waset.org/pdf/9997982 PU - World Academy of Science, Engineering and Technology NX - Open Science Index 87, 2014 N2 - In economical evaluation literature, although the combination of some variables such as repair and maintenance costs and accumulated use hours has been widely considered in determining of optimum life for tractor, no investigation has indicated the influence of failure rate on repair and maintenance costs. In this study, the owners of three hundred tractors, which include Massey Ferguson, John Deere and Universal, were interviewed, from five regions of Khouzestan Province. A regression model was used to predict the tractors annual repair and maintenance costs based on failure rate. Results showed that the maximum percentage of annual repair and maintenance costs occurred in engine parts for MF285, JD3140 and U650 tractors while these costs for tire, ring, ball bearing and operator seat were higher compared to other MF399 tractor systems. According to the results of the regression, the failure rate increase would lead to annual repair and maintenance costs increase for all tractors. But, of all the tractors, repair and maintenance costs of JD3140 tractors extremely affected by the failure rate increase. ER -