Abstract
Agile development methods were believed to best suit small, co-located teams, but the success in small teams has inspired use in large and very large-scale software development. However, fundamental assumptions of agile development are challenged when applying the methods at a very large scale. An interpretative revela- tory case study on one of the largest software development programmes in Norway shows how agile methods were adapted and complemented with practices from tradi- tional methods to handle the scale. The programme ran over four years with 12 co- located development teams and a total of 175 people involved. The case study was conducted retrospectively using group interviews with 24 participants and documents. Findings on key challenging areas are reported: customer involvement, software archi- tecture, and inter-team coordination. The revelatory study also suggests refinements of a research agenda for very large-scale agile development.