Design can have a significant role in improving the environmental and business performance of products and services, but only if it is properly integrated to product and service development. Through a single case study on the development process of the Viking Line Grace passenger ship, this dissertation studies how design is integrated to complex and networked product development. The results of the study show that while design held a central role in designing the passenger interfaces of the ship, making change in other domains - such as sustainability - was far more challenging than what could be hypothesized on the basis of design theory. This was duw to the complexity of the ship as a product and how complexity is managed in shipbuilding processes.