A fuzzy regression approach to hierarchical evaluation model for oil palm grading

Measurement of quality is an important task in the evaluation of agricultural products. The inspection process is normally pursued on visual inspection basis according to the ripeness standards of the crop, and this grading is subject to expert knowledge and interpretation. Therefore, the quality inspection process of fruits needs to be conducted properly to ensure that good quality fruit bunches is selected for production. Moreover, it needs to be considered during the evaluation that human subjective judgments make the fruit grading inexact. Hence, the objectives of this paper are to build a fuzzy hierarchical evaluation model that characterizes criteria of oil palm fruits, and to decide the fuzzy weights of these criteria based on a fuzzy regression model. A numerical example is included to illustrate the computational process of the proposed model.