Cereals mechanized harvest logistics.

Author(s)

Saulo Salaber Souza e Silva

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2004-06-24

Examining board members

Marcos Milan; Antonio Jose da Silva Maciel; Jose Paulo Molin

• Advisor: Marcos Milan

Abstract

Cereals production constitutes one of the most important agricultural activities to Brazil. The country occupies leadership positions in the world production, and it is one of the main exporters. So that such performance be each time more overcame, the market requests competitive production costs, and this is one of the brazilian agriculture great current challenges. Focusing the ton final production cost percentages distribution, the harvest operation is prominence among the main cereals cultures productive process stages. For corn and soybeans cultures, the cost of their activities oscillates among 30 to 40% of the total operations costs. By such significance, optimization strategies that seek for the reduction of its operational cost, and that create conditions for an better harvest planning become more and more necessary. Considering the application of logistical concepts in the harvest operation planning and coordination as a potential resource to the reduction of its cost and improvement of its accomplishment, the present work had for objective to analyze logistical strategies in cereals harvest systems. Due to the complexity of their interrelations, and to the involved variables number, it was decided to base the analyses on a computational simulation model. SisColhe was the chosen name to the logistics and cereals harvest simulation developed software. The simulations that compose the study happened taking in granted three hypothetical sceneries. The evaluation of the harvest strategies was oriented by six different analyses, comprising the initial problem definition and the development of the simulation algorithm, the program results validation, the most cost composition parameters identification and the cost structures and machinery operational performance behavior understanding. The results demonstrated that the fixed components have more participation in the harvest final cost composition than the varied ones, and the larger contribution factor to the capital a port is the value with which the harvesters are acquired. The fleet harvesters operational capacity is the parameter of largest cost reduction potential, since its influenced, besides, the performance of the others fleet equipments, demonstrating a systemic behavior among them. Taking in granted the cost of the production movement, the vehicles charge and discharge activities were the responsible for the largest transport costs portion. In the harvest planning, the correct fleet dimensioning, together with the adoption of performance increment alternative strategies were viable strategies in high productions and small time intervals characterized systems. The simulations results demonstrated that the SisColhe software is capable to aid the analysis and the evaluation of the cereals mechanized harvest. The machinery behavior logic and its interrelations could be reproduced. The validation differences were acceptable due to the algorithm simplifications imposed and to the intrinsic agricultural environmental variability. (AU)