Requirements problems in the development of a new user interface for healthcare equipment

In August 2013, our company started work for an industrial customer. First, we developed a prototype and conducted field studies in small-scale projects. This was successful and the basis for a larger project about development of a new user interface for healthcare equipment. A main aim for us was to use this project as starting point for establishing a strategic, long-term relationship with this customer. However, we were not successful. In November 2014, our customer chose to take over the development themselves. We were too expensive, used too many hours and were not able to provide useful estimates, they said. In this paper, we describe the project and analyze causes to our customer's decision. We also look at possible alternatives to the actions we took in the project and discuss whether we could have done better. A root cause to our customer's dissatisfaction is related to requirements and handling of requirements.