This document discusses a case study conducted to improve a collaborative design process called Symphony. The case study evaluated the Symphony method, which was developed for information systems design and extended to support mixed reality system design. Participants worked individually and collaboratively using the Symphony method on a sample project. Results found that the method facilitated collaboration between users and specialists from software engineering and human-computer interaction domains. Feedback also suggested simplifying the process and documentation. The case study provided insights for validating and improving the extended Symphony process.