In order to analise the sugar cane harvest process of a mill, a model was developed representing the operations of mechanical loading, field tractor towing and transporting of sugar cane to the plant. To estimate the average speed of the vehicles on the highways and the operational capacities of loading, empirical equations were developed from the data gathered from a sugar mill located in the state of Sao Paulo, in Brazil. Time keeping records were elaborated of various operations determining for each of them timetables according to the rhythm: slow, medium and rapid. Operational costs were estimated through methodologies found in the literature and the real performance data of the mill. To validate the model, estimated data were compared to real ones from the sugar mill and other enterprises and a good correlation was found. Estimated costs were very similar too. Sensitivity analysis were developed for the operational cost of each operation and the total costs. The parameters that most contribute to costs increase were labor and time lost. On the other hand, truck capacity and operational efficiency were the parameters that most contribute to cost decrease. Using the model it was also possible to choose equipments. Bigger equipments (103 kW tractors, 1.500 kg loaders and 55 t trucks) are cheaper than smaller ones when the transport distance is more than 5 km.
