Reconciling agility and architecture: a theory of agile architecture

The purpose of agile software development is to enable the software development team to respond to change and learn from change so that it can better deliver value to its customer. If an agile software development team spends too much time planning and designing architecture up-front then the delivery of value to the customer is delayed or otherwise compromised, and responding to change can become extremely difficult. Not doing enough architecture design increases exposure to risk and increases the chance of failure. The balance between architecture and agility is not well understood by agile practitioners or researchers.  This thesis is based on grounded theory research involving 44 participants from 36 organisations, all working in agile software development and who are either experienced in architecture design or are closely involved with architecture. The thesis presents a theory that describes how agile software teams design an agile architecture with reduced up-front design and which is able to respond to change, helping teams find a balance between architecture and agility.  The theory describes six forces that affect the agility of the architecture and up-front design, and five strategies that teams use in response to those forces to determine how much effort they put into up-front design. Understanding these forces and strategies helps agile teams to determine how much up-front design is appropriate in their contexts.