Robust Design Tutorial
Quality Engineering (QE) is a series of approaches to predict and prevent the troubles or problems that might occur in the market after a product is sold and used by the customer under various environmental and applying conditions for the duration of designed product life (Wu & Wu, 2000: 1). Robust design has been developed to improve product quality and reliability in industrial engineering (Park et al. 2006: 181).
Robustness is the state where technology, product, or process performance is minimally sensitive to factors causing variability and aging at the lowest unit cost (Taguchi et al. 2000). Lack of robustness is synonymous with excessive system variation, resulting in quality loss, which could be minimized if the system functioned on-target all of the time, despite the noise (Wang, 2005: 151).
Unplanned deviations occur due to variations in various engineering processes. Robust design is one of the methods that can be implemented in engineering processes to prevent those unplanned deviations. Suh (1990) says that “robust design is defined as the design that satisfies the functional requirements even though the design parameters and the process variables have large tolerances for ease of manufacturing and assembly.” This definition states that the information content is minimized. Box and Fung (1993) say that “robustifying a product is the process of defining its specifications to minimize the product’s sensitivity to variation.”