A robust product-service system design method based on Taguchi Method

Product-service system (PSS) is an integrated system that delivers additional value to stakeholders through combining products and services. For a PSS to succeed, it is critical that its design accurately reflects the value propositions of diverse stakeholders and converges on an optimal configuration. However, this is challenging because stakeholder requirements often conflict, and the perceived value is subject to interference from contextual noise. Furthermore, prevailing PSS design methodologies lack robust design methods that support designers in identifying configurations that remain effective under such variations. To address this gap, this study proposes a novel robust design method that integrates the Customer Journey Job Map (CJJM) with the Taguchi Method (TM). The CJJM structurally decomposes stakeholder value propositions into context-specific service tasks, which serve as the control factors for TM. The TM then identifies the optimal task configuration that maximises service completion levels while minimising performance variation induced by noise factors. A case study on a shared meeting service robot validates the proposed method. The results confirms that the method helps designers identify user preferences across service stages and determine the most robust design solution. This study provides a structured method for designing value-robust PSS under requirement conflicts and contextual uncertainty.