This paper reports an empirical study which examines the future relevance of service design practice using a qualitative approach, consisting of in-depth interviews with design professionals predominantly located in the UK. The findings show the diverse views towards how service design is applied in practice and how it is perceived as a discipline, suggesting that service design is not considered as a unified practice, but a range of practice used in diverse contexts. It identifies the value of service design as delivering both knowledge and solutions whereby service designers can act as enablers and/or doers. It reveals a consensus amongst practitioners for the necessity of a collaborative process and mindset, as well as the use of a set of skills and tools. The research brought to light a move from a solely human-centric ethos towards an expanded one that includes systems thinking. One key finding, looking towards the future value of service design, is the shift towards a transdisciplinary approach, an under-noticed possible direction which could bring significant impact to solving complex and wicked problems that is worthy of continued investigation.