A. Sharafi a
, M. Aminnayeri a
, Amirhossein Amiri b,∗
a Department of Industrial Engineering, Amirkabir University, Tehran, P.O. Box 15875-4413, Iran
b Department of Industrial Engineering, Faculty of Engineering, Shahed University, Tehran, P.O. Box 18151-159, Iran
Received 18 January 2012; revised 30 May 2012; accepted 16 October 2012