Quality-Oriented Requirements Engineering for Agile Development of RESTful Participation Service

Decision-making between humans is a recurring challenge in a society where consensuses for disagreements have to be found. To support such decision-makings, at the Karlsruhe Institute of Technology a Participation Service is developed as part of a service-oriented campus system in an agile manner and based on the Representational State Transfer (REST) paradigm. One of the key success factors of such software projects is the requirements engineering process. Scenarios are an appropriate way to describe a system from the user's point of view. However, existing methodologies do not specify quality requirements for these scenarios. This article presents an enhancement of existing scenario-based requirements engineering techniques to fulfill the quality characteristics of the international standard ISO/IEC/IEEE 29148 and align the quality aspects to the product strategy. We illustrate the approach and the resulting quality improvements by eliciting functional and non-functional requirements for the Participation Service in an agile manner, while considering constraints emerged from the existing RESTful system.