This paper introduces a case study intended for verifying, evaluating and improving technologies for a practical service; its process is analyzed using the design thinking approach. We develop and evaluate two technologies for disaster situations; a resilient information sharing platform and a mutual safety confirmation application on the platform. The case study includes a variety of verifications and evaluations such as a system work test in a disturbed public space, a larger scale system work test, and user acceptance evaluations that address both usability and psychological factors. The heart of our improvement process is it repeated back-step in the service design process for more efficient incremental advancement. We advance the field of technology research and service design research by providing guidelines for technology improvement and/or service design through the introduction and analysis of the practical case study.
