Abstract
Purchasing and maintaining agricultural machines are two of the most considerable costs of the agricultural sector, which includes farm equipment manufacturers, farm contractors and farms. In this context, repair and maintenance costs (R&M costs) generally constitute 10%-15% of the total costs related to agricultural equipment and tend to increase with the age of the equipment; hence, an important consideration in farm management is the optimal time for equipment replacement. R&M cost estimation models, calculated as a function of accumulated working hours, are usually developed by ASAE/ASABE for the agricultural situation in the United States, which is considerably different than agricultural context of other countries. So, the goal of this work is to recalculate model parameters according to the Italian situation. For this purpose, data related to 20 self-propelled combine harvesters in Italy were collected. According to the model, which was obtained by interpolating the data through a two-parameter power function (as proposed by the literature), the R&M cost incidence on the list price of Italian self-propelled combine harvesters at 3,000 working hours (estimated life of the machines) was 23.1% as compared with 40.2% calculated through the most recent U.S. model