An efficient heuristic approach to total flowtime minimization in permutation flowshop scheduling

The problem of permutation flowshop scheduling is considered with the objective of minimizing the total flowtime. We present a constructive heuristic and two composite heuristics to solve the problem. The composite heuristics combine the simulated annealing method of Chakravarthy and Rajendran [Production Planning and Control 10 (1999)], the constructive heuristic of Nawaz et al. [Omega 11 (1983)] and the new heuristic. Computational analysis is carried out with the benchmark problems of Taillard [European Journal of Operational Research 64 (1993)]. The two composite heuristics produce better quality solutions than those produced by the composite heuristics of Liu and Reeves [European Journal of Operational Research 132 (2001)]. Statistical tests of significance are used to substantiate the improvement in solution quality.