Optimizing injection molding toward multiple quality and cost issues

injection-molding part designers are frequently faced with multiple quality and cost issues, These issues are usually in conflict with each other; thu s, a trade-off needs to be made to reach a final compromised solution. Beca use evaluation of part quality and cost via injection-molding simulation is very time-consuming, implementation of a conventional multicriteria optimi zation procedure for injection-molding problems is economically unfavorable . However, many injection-molding problems dealing with multiple quality an d cost issues can be modeled as constrained problems, with the total cost a s the objective function and quality quantities as the constraints. By intr oducing a concept of penalized total cost, such constrained problems are fu rther simplified into bounded single-criterion problems. The bounded single -criterion problems are then optimized using a direct search-based optimiza tion procedure. Strategies of modeling, transformation, and optimization fo r these problems are discussed in this article. A case study is provided.