“…In general, the approaches can be classified as exact or heuristic and grouped according to the methodological concepts they use. Among others, the concepts employed in exact algorithms include branch and bound (Aksoy, 1990;Mavrotas and Diakoulaki, 1998;Ramesh, Karwan, and Zionts, 1989, 1990, 1991Shin and Allen, 1994), dynamic programming Karwan, 1981, 1982), implicit enumeration (Klein and Hannan, 1982;Pasternak and Passy, 1973), reference directions (Karaivanova et al, 1995;Narula and Vassilev, 1994), weighted norms Climaco, 1999, 2000;Eswaran, Ravindran, and Moskowitz, 1989;Karaivanova, Narula, and Vassilev, 1993;Neumayer and Schweigert, 1994;Schandl, Klamroth, and Wiecek, 2001;Solanki, 1991;Steuer and Choo, 1983), weighted sums with additional constraints (Chalmet, Lemonidis, and Elzinga, 1986;Ferreira, Climaco, and Paixão, 1994;Neumayer and Schweigert, 1994), and zero-one programming (Bitran, 1977(Bitran, , 1979. Heuristic approaches, such as simulated annealing, tabu search, and evolutionary algorithms, have been proposed for multiobjective integer programs with an underlying combinatorial structure (Ehrgott and Gandibleux, 2002).…”