Agile Scalability Requirements

Many software organisations struggle to provide appropriate levels of scalability in their software systems. Agile development rests on pragmatic and value-centred approaches to requirement capture that allows customers and vendors to interact in the process of producing the software system that best mets the real needs of the customers. In collaboration with Norwegian software organisations we have observed that setting scalability requirements is hard. Organisations struggle because they lack a conceptually sound language for expressing scalability requirements. To improve current practice, we propose a light-weight and flexible approach to specifying scalability requirements. Flexibility ensures that a more extensive characterisation can be used if higher precision is required, and more information becomes available.