“…Second, the machine-part matrix does not show the sequence of operations for each part; hence, it may face a problem when counting the number of intercell trips. Due to the NP-Complete property, the cell formation problem is difficult to solve; thus, numerous studies have applied heuristic methods to solve cell formation problems, such as simulated annealing algorithms (Boctor, 1991;Chen and Srivastava, 1994;Baykasoglu, 2004;Wu et al, 2009), tabu search algorithms (Sun et al, 1995;Onwubolu and Songore, 2000;Belarmino et al, 2001) and genetic algorithms (Gupta et al, 1996;Hwang and Sun, 1996;Lee et al, 1997;Chan et al, 1998;Mak et al, 2000;Onwubolu and Mutingi, 2001;Vin et al, 2005;Wu et al, 2007;Defersha and Chen, 2008;Deljoo et al, 2010).…”