Optimizing the decision-making process for large-scale design problems according to criteria interrelationships

As the scope of elements considered by product designers has widened, the number of design criteria and variables has mushroomed. Broad concerns, such as product life cycle as well as specific and detailed user requests, must all be addressed and their respective priorities balanced. Companies now face a twofold difficulty with design projects: the need to deal with them as large-scale optimization problems and the need to shorten the development cycle to a certain period. With respect to the design stage, this paper proposes a concurrent criteria-sequencing method for large-scale design optimization problems that not only yields an optimum criteria order for evaluation, but also shows which criteria can be evaluated in parallel. This method consists of two main techniques based on criteria interrelationships: the selection of criteria blocks (i.e. collaborative blocks and parallel blocks) and the sequencing of both the criteria blocks and the criteria within them, with the aim of minimizing the design time. Using a hierarchical decomposition approach, the relationships between each criterion and the design variables of which it is composed are clarified, resulting in the selection of closely interrelated criteria, which are then arranged in blocks. To demonstrate the method's effectiveness, it is applied to the design of an urban bicycle.