In order to solve complex product design optimization problems which contain both discrete and continuous
variables, a mix-variable collaborative design optimization method is proposed based on collaborative optimization(CO)
which is an efficient way to solve mix-variable design optimization(MDO) problems. With the thought of “divide and rule”,
the method decouples the problem into some relatively simple subsystems, Then by using CO’s collaborative mechanism,
the optimal solution is obtained. Finally, the result of a case study shows the feasibility and effectiveness of this method.