User experience is what the end user encounters: the kiosk, its interface, and the resulting notification on mobile. Service design is the orchestration of technology, people, and processes that makes the user’s experience possible: pinging the server, connecting the request with the right support agent, and documenting the outcome.
На мой взгляд, NNGroup довольно хорошо показали где UX, а где Service Design
https://www.nngroup.com/articles/ux-vs-service-design/
