A multilevel global optimization approach considering product realization process alternatives and parameters of these alternatives is proposed to improve manufacturability measures, including feasibility, cost, and time of production. Development of product realization processes is described by an AND/OR graph. A feasible product realization process alternative can be identified from this graph and is described by a number of parameters. The optimal parameters regarding a product realization process alternative are achieved at the parameter optimization level, while the optimal alternative is obtained from all the feasible alternatives. Two global optimization methods, genetic algorithm and simulated annealing, are employed for identifying the optimal product realization process alternative and its parameters. The introduced approach serves as a key component in an integrated concurrent design system. A case study example is given to show how the proposed method is used for solving engineering problems.