Abstract: For solving the problem of low productivity and low machine utilization caused by unreasonable assignment in tire vulcanizing process, an improved Discrete Harmony Search (Improved Harmony Search, IHS) Algorithm was proposed to optimize the maximum completion time of vulcanizing workshop scheduling. This algorithm has three processes including individual memory consideration process, disturbance search process and competitive selection mechanism. In the competitive selection mechanism, the corresponding individual in harmony memory or worst solution was replaced with new solution and harmony memory was updated. That strategy made each individual in memory more quickly fly to the optimal solution. The algorithm was simulated on MATLAB. The results show that IHS is superior to HS and PSO algorithm. This algorithm can efficiently solve the vulcanizing shop scheduling problem, and the analysis demonstrates the validity and feasibility of the algorithm.

Key words: Discrete optimization algorithm, Harmony search algorithm, Harmony memory, Vulcanization workshop scheduling