Abstract: Abstract: Aiming at the integrated of process planning and scheduling （IPPS）， a mathematical model is established based on AND/OR disjunction graph and the concept of “combination” to minimize the makespan optimization target. An integer coding scheme is designed， which does not need to generate a processing path for the workpiece in advance， can deal with process planning and scheduling problems at the same time. Due to the effect of the initial solution on the algorithm’s ability to find the optimal， the load of the machine is considered to improve the quality of the initial population when the population is initialized. The plug-in method is used to generate active scheduling during decoding to shorten the overall processing time. The discrete mayfly algorithm is used to solve IPPS， and the Metropolis criterion is used to receive poor solutions， and the adaptive factors are introduced to improve the convergence speed of the algorithm， and a local search algorithm is designed to improve the accuracy of the algorithm. Finally， large-scale benchmark studies are carried out and compared with other algorithms to verify that the algorithm has good optimization performance.

Key words: Key words： integrated of process planning and scheduling, mayfly algorithm, adaptive factor, integer encoding scheme