Abstract The World Health Organization (WHO) highlights the significant threat that unsustainably long working hours pose to our mental and physical well-being. Aligning with this concern, an Agile principle emphasizes that “Agile processes promote sustainable development.” However, previous work in 2023 debunked this notion of inherent stability in Agile systems, such as the Scrum and Kanban frameworks. In this study, we aim to analyse the relationship between system stability and the tendency of teams to work outside reasonable office hours. We inspect 295 historic Agile projects completed in intive, a software development company. We assess the percentage of late-night, early-morning, or weekend hours where a Product Backlog Item (PBI) was created or resolved and compare this percentage of Unsustainable Hours metric to the Stability Metric and the number of Inventory Days remaining. The analysis showed that almost no correlation exists between the Unsustainable Hours worked and either the system stability or outstanding inventory. These findings indicate that, while working unconventional and potentially excessive hours is a concern, it does not appear to be linked to the stability of Agile systems. This highlights the need for a deeper understanding of individual and team motivations to foster long-term sustainable work practices.

Abstract Agile systems, like the Kanban and Scrum frameworks, are built on assumptions of sustainability and stability, however, there is little empirical evidence on whether such systems are stable in practice or not. Therefore, in this study we aim to inspect the stability of Agile systems by leveraging the concept of stability described in Queueing Theory. We define a novel metric, the Stability Metric, as a way of assessing queueing systems, especially Agile systems. We inspect 926 Jira projects in 14 organizations with over 1.6 million product backlog items using this metric. The analysis showed that 72.89% of these Jira projects were not stable and stable systems, on average, had product backlog sizes 10 times shorter than unstable ones. These results suggest that while the goal of Agile is to create a sustainable, stable way of working, this is not guaranteed, and a better understanding of systems and queues may be required to help design, create, coach, and maintain optimal Agile systems.