Abstract: This paper considers the scheduling problem of hybrid flow shop scheduling which the involves total number of tardy jobs. An improved simulated annealing algorithm is proposed for its solution. The initial seed solution is obtained by a heuristic algorithm, then optimizes the solution by the simulated annealing algorithm. New schedule can be obtained by selecting two jobs randomly and interchanging them. In conjunction with the first come first service  rule and first available machine rule to construct a schedule for the overall stages. Numerical results indicate the algorithm is feasible and efficient.

Key words: tardy jobs, hybrid flow shop scheduling, simulated annealing algorithm