Fuzzy goal programming approach for multi-objective multi-mode resource constrained project scheduling problem

This research proposes fuzzy goal programming model for multi-objective multi-mode resource constrained project scheduling problem. Objectives of the problem are minimization of the total time and the total cost of the project. Currently, objective in a multi-mode resource constrained project scheduling problem is often limited to a single objective function. Moreover, all elements of cost functions in a project are not included in the cost objective function. Incomplete total project cost causes errors in finding the project scheduling time. In this research there methods;1)goal programming, 2) fuzzy linear programming and 3) preemptive fuzzy goal programming are used to solve the multi-objective multi-mode resource constrained project scheduling problem. These methods can find the compromise solution of the problem. However, the proposed preemptive fuzzy goal programming is more flexible than the others because it can adjust to find variety of alternative solutions

Solving Tea Blending Problems Using Interactive Fuzzy Multi-Objective Linear Programming

Blending is a classical and well-known optimization problem that has been applied in the food, steel, and composite material industries. However, tea blending is more complicated than general problems due to the variety of products, processes, and sources of raw materials and semi-products. So, in this research, a fuzzy multi-objective model for the tea blending problem was proposed to minimize the total production cost and the deviation of quality target score; it provides a more robust and flexible method than existing models for complex real-world problems. Existing research works of a blending problem consider only raw material cost, but semi-product cost and processing cost are included in the proposed model that matches the actual case. Losses that occur during production are also incorporated. The selection of appropriate raw materials and semi-product sources can be obtained with the preferred levels of cost and quality by the proposed algorithm. The interactive fuzzy multi-objective programming to solve the problem has advantages over existing interactive programming methods. It is easy to manipulate interactively to obtain more efficient solutions than existing methods and both balanced and unbalanced solutions can be selected. The comparison of the results of an existing approach and the interactive fuzzy multi-objective programming algorithm for the tea industry is illustrated