Addressing highly dynamic changes in service- oriented systems: Towards agile evolution and adaptation

This chapter sets out to introduce relevant foundations concerning evolution and adaptation of serviceoriented systems. It starts by sketching the historical development of software systems from monolithic and mostly static applications to highly-dynamic, service-oriented systems. Then, it provides an overview and more thorough explanation of the various kinds of changes that may need to be faced by serviceoriented systems. To understand how such changes could be addressed, the chapter introduces a reference service life-cycle model which distinguishes between evolution, viz. the manual modification of the specification and implementation of the system during design-time, and (self-)adaptation, viz. the autonomous modification of a service-oriented system during operation. Based on the discussion of the key activities prescribed by that life-cycle, the chapter elaborates on the need for agility in both adaptation and evolution of service-oriented systems.