A novel particle position updating strategy is presented based on the chromosome coding scheme of operation
sequencing and machine allocation. This strategy makes the particle swarm optimization(PSO) algorithm work directly in
the discrete domain, and machines are allocated many times to operations to expand search scope. An improved simulated
annealing technique is introduced to enhance the neighborhood search of PSO algorithm, which efficiently balances the
exploration and exploitation abilities. Finally, a numerical example and an electro-acoustic enterprise cone shop example are
given to show the effectiveness and feasibility of the proposed algorithm.