Towards Agile Scalability Engineering

Scalability engineering is currently not well integrated into agile development techniques. This paper extends agile development techniques so that scalability can be handled in an incremental and iterative development process. By scalability we mean the ability of a system to handle increasing workload. We propose the ScrumScale Method which includes scalability engineering in Scrum. This extension should also be applicable to other agile techniques. For scalability testing, we indicate how quality thresholds should be scaled up or down according to the degree of completeness of the product, test hardware, test software, test data and test workload. Using action research, we have conducted three pilots in three Norwegian software organizations. These three pilots have different architectures and operate in different markets yet have in common scalability challenges.