Fuzzy evaluation of cogeneration alternatives in a petrochemical industry

This paper derives fuzzy net present value (NPV) and pay back year (PBY) models as decision indexes for cogeneration alternatives decision-making. The Mellin transform is employed to establish the means and variances of the fuzzy indexes in order to rank various cogeneration alternatives. It is noted that the mean and variance values depend only on the vertexes of the fuzzy index, and are independent of their height. The current paper verifies the performance of the proposed models by simulating two numerical examples and by considering a cogeneration program in a petrochemical industry. It is shown that the results of the proposed fuzzy economic models are consistent with those of the conventional crisp models, and that the developed concepts are straightforward and easily implemented compared to the fuzzy ranking methods proposed in previous studies. Furthermore, the developed methods serve as readily implemented sensitivity analysis tools for use in the arena of uncertain decision-making.