Robust modular product family design using a modified Taguchi method

The Taguchi method is very effective in improving quality and decreasing cost while increasing the robustness of designs. However, it is an 'open control system' that relies on experiments to determine the optimal levels of control factors. The critical information about how the quality characteristic is affected by changes in the control factor is not considered in the experimental design process. This paper proposes a modified Taguchi methodology by introducing the feedback of quality characteristics to improve the robustness of modular product families against changes in customer requirements to efficiently determine the optimal control factors and the corresponding suitable time periods for designing robust product families. The research questions addressed in this paper include: How to efficiently optimize control factors in the design of product families? How to measure the robustness of a product family for meeting current and future needs? How far into the future should designers look in while designing a robust product family? This paper demonstrates the application of our methodology using a simplified example of a vacuum product family to determine the optimal module instances that need to be deployed in the future.