A study of safety documentation in a scrum development process

Context: There has been an increasing use of agile techniques for safety-critical systems. Agile techniques embrace fast changing requirements, continuously delivered products and frequent communication with lightweight documentation. Motivation: However, for safety-critical system projects, a lack of safety-related documentation influences the safety-related communication and may reduce the safety assurance's capability. Objective: In this article, we aim to improve the safety-related documentation in a Scrum development process and to support a more efficient safety-related communication. Method: We investigated three types of safety-related documentation patterns in agile development: safety epic, safety story, and agile safety plan. We further adapted and implemented them in a student project at the University of Stuttgart, Germany. We used participant observation, Scrum artifacts, documentation review, and questionnaires combined with interviews to validate this adapted documentation concerning their effect on communication, safety culture, and general impact on organization. Result: The results showed that safety story and safety epic have a positive effect on both internal and external communication. However, the agile safety plan showed little effect on communication. Rather, it has general impact on the safety process overview, priority management, providing a safety backup knowledge as well as having a delivered safety assessment report. Conclusion: To improve safety-related communication in a Scrum development process for safety-critical systems, the safety story and the safety epic are strongly suggested, while an agile safety plan should be further investigated depending on its general impact in various projects.