Studies of tractor maintenance and replacement strategies of Wonji Shoa Factory, Ethiopia.

This study mainly focuses on tractor maintenance and replacement strategies to assess the impact of various parameters on the economic life of tractors in order to improve the value of a profitable management choice on selected tractor samples. Considering the preventive replacement policy, the total annual costs were estimated taking into account the repair and depreciation costs. At a 95% level of confidence for each approach, the statistical analysis program "IBM SPSS Statistics 26" was used. An empirical relation based on multiple regression analysis has been generated to predict the economic operational life of a tractor using per-unit repair cost and annual usage (hours). From the analysis, John Dear 333, SAME 130, New Holland 80, and Massy Ferguson 150 are not supposed to be used economically in the field after the fifth, seventh, sixth, and eighth years respectively at Wonji Shoa Sugar Factory due to increasing maintenance cost in present condition. [ABSTRACT FROM AUTHOR]