Abstract
This study aims to understand the product development process that integrates product design while maintaining brand consistency over time. For long-term brand survival, sustaining consistency and fostering innovation to continuously adapt to market changes has been recognized as essential. However, there has been limited understanding of how product design contributes to longevity within the development process. To address this gap, we reviewed previous studies on long-selling branding and universal design, analyzing the development process of two long-selling Otsuka Pharmaceutical products. Our case study analysis identified eight key phases common to both products: 1. research, 2. insight, 3. essentialization, 4. exploration, 5. development, 6. universalization, 7. diffusion, and 8. extension. The discussion highlights that product design aligned with sustainability and innovation can be realized when essentialization and universalization are adequately incorporated into the development process.
