Understanding the role of requirements artifacts in kanban

User stories are a well-established way to record requirements in agile projects. They can be used as such to guide the daily work of developers or be split further into tasks, which usually represent more technical requirements. User stories and tasks guide communication and collaboration in software projects. However, there are several challenges with writing and using user stories in practice that are not well documented yet. Learning about these challenges could raise awareness for potential problems. Understanding how requirements artifacts are used for daily work could lead to better guidelines on writing stories that support daily work tasks. Moreover, user stories may not be appropriate to capture all kinds of requirements that are relevant for a project. We explore how to utilize requirements artifacts effectively, what their benefits and challenges are, and how their scope granularity affects their utility. For this, we studied a software project carried out in the Software Factory at the Department of Computer Science, University of Helsinki. We investigated the requirements artifacts and then interviewed the developers and the customer about their experiences. Story and task cards have helped the participants throughout the project. However, despite having a Kanban board and rich communication within the team, some requirements were still too implicit, which also led to misunderstandings. This and other challenges revealed by the study can guide future in-depth research.