H. Amoozad-Khalili, M. Ranjbar-Bourani, S. M. J. Mirzapour Ale-Hashem/ TJMCS Vol .1 No.4 (2010) 321-332 321 Available online at http://www.TJMCS.com The Journal of Mathematics and Computer Science Vol .1 No.4 (2010) 321-332 Fuzzy Demand Consideration in a Multi-Objective Dynamic Cell Formation Problem Using a Robust Scatter Search Hossein Amoozad-Khalili 1,* , Mehdi Ranjbar-Bourani 2 , S.M.Javad Mirzapour Ale-Hashem 3 Faculty Member of Islamic Azad University-Nowshahr Branch, Nowshahr, Iran, amoozad_ie@iauns.ac.ir Department of Industrial Engineering, I.A.U., South Tehran Branch, Tehran, Iran, ranjbar.mehdi@yahoo.com Department of Industrial Engineering, Iran University of Science and Technology, Tehran, Iran, b.mirzapour@gmail.com Received: July 2010, Revised: October 2010 Online Publication: December 2010 Abstract This paper presents a multi-objective cell formation problem considering alternative process routes and machine utilization with fuzzy demand. Two conflicting objectives include the total cell load variation and sum of the other costs consisting machine cost, inter-cell material handling cost, parts purchasing, operation, maintenance, and reconfiguration of machines cost are to be minimized simultaneously. Moreover, we consider demand in fuzzy condition, because it is more realistic to take into account the inexact and uncertain nature of demand. Due to the complexity of this problem, we develop a scatter search algorithm. Also by using the Taguchi as a robust parameter design method, we tune the effective factors of the developed algorithm on two sizes of benchmark problems that are generated randomly. NSGAII and Scatter Search evaluated and the related results confirm the efficiency and the effectiveness of our proposed Scatter Search provides good output according to some quality measures, especially for large-sized problems. Keywords: Cell formation problem, fuzzy demand, scatter search, Taguchi design 1. Introduction In many practical cases, a product mix or demand level may vary under a multi-period 1,* Corresponding author: MSc in Industrial Engineering 2 MSc in Industrial Engineering 3 Ph.D Candidate in Industrial Engineering The Journal of Mathematics and Computer Science