Fuzzy TOPSIS method with ordered fuzzy numbers for flow control in a manufacturing system

The aim of the paper is to present a practical solution to a particular real-life problem of discrete flow control in a manufacturing system. For this purpose a fuzzy Multi-Criteria Decision Making (MCDM) method, which is an extension of the Fuzzy Technique for Order Preference by Similarity to Ideal Solution (FTOPSIS) approach using Ordered Fuzzy Numbers (OFNs), is used. The paper includes a case study of the application of this method as a flow controller for the transport trolley in a flexible manufacturing system. The immediate aim of control is to choose the transport trolley's destination (production line). A set of criteria (parameters) for the evaluation of the flow's destination is suggested, related to time efficiency and equal workload of machines. The advantage of the proposed method is its ability to distinguish the type of criteria (benefit, cost) by using the orientation of ordered fuzzy numbers. An example of calculations using the presented method is shown and the results of the method, based on the simulation of a manufacturing system, are presented. The results thus obtained are compatible with flexible automation. In order to test the FTOPSIS method with OFNs the proposed flow control method is compared with the TOPSIS method and other simple control methods (dispatching rules). The proposed method is more efficient than the methods used for comparison and can be effective and efficient for diversified production and fast, automatic changeovers on production lines. (C) 2016 Elsevier B.V. All rights reserved.