Discovering, Analyzing, and Managing Safety Stories in Agile Projects

Traditionally, safety-critical projects have been developed using the waterfall process. However, this makes it costly and challenging to incrementally introduce new features and to certify the modified product for use. As a result, there has been increasing interest in adopting agile development paradigms within the safety-critical domain. This in turn introduces numerous challenges. In this paper we address the specific problems of discovering, analyzing, specifying, and managing safety requirements within the agile Scrum process. We propose SafetyScrum, a methodology that augments the Scrum lifecycle with incrementally applied safety-related activities and introduces the notion of 'safety debt'' for incrementally tracking the current safety status of a project. We demonstrate the viability of SafetyScrum for managing safety stories in an agile development environment by applying it to a project in which our existing Unmanned Aerial Vehicle system is enhanced to support a River-Rescue scenario.