A posterior preference articulation approach to reliability improvement experiments considering loss costs of manufacturer and customer

Design of experiments (DOE) can help engineers to identify important experimental factors and determine their optimal operating conditions to improve product reliability. Reliability improvement reduces loss costs of manufacturer and customer. Design lifetime and warranty period are two crucial parameters in product life cycle. In this article, we present renewal process within warranty period to describe manufacturer's loss cost. Meanwhile, we employ the stress-strength model to describe customer's loss cost within the design lifetime. Expected loss costs of manufacturer and customer respectively are calculated. Then we introduce a posterior preference articulation approach to reduce the loss cost of manufacturer considering the constraint of customer's loss cost. The proposed method is illustrated through a real example. The result shows that the optimal solution is different comparing with other methods. Moreover, we get the optimal solutions under different design lifetimes and warranty periods. We find that the optimal solution may be changed. It means that the manufacturing process parameters need to be readjusted if design lifetime and warranty period are redesigned.