We recommend adopting evolutionary architecture as an alternative to traditional up-front, heavy-weight enterprise architectural designs.

In contrast to traditional up-front, heavy-weight enterprise architectural designs, we recommend adopting evolutionary architecture. It provides the benefits of enterprise architecture without the problems caused by trying to accurately predict the future. Instead of guessing how components will be re-used, evolutionary architecture supports adaptability, using proper abstractions, database migrations, test suites, continuous integration and refactoring to harvest re-use as it occurs within a system. The driving technical requirements for a system should be identified early to ensure they are properly handled in subsequent designs and implementations. We advocate delaying decisions to the latest responsible moment, which might in fact be up-front for some decisions.

One principle of agile software development is the notion of the last responsible moment. This notion applied to architectural considerations is controversial among traditional architects. We believe that, given properly articulated principles and appropriate test suites, architectures can evolve to meet the changing needs of a system, allowing for architectural decisions to be made at the last responsible moment without compromising the integrity of the system. We call this approach evolutionary architecture, in that we allow the architecture to evolve over time, always respecting the architectural guiding principles.

We assist many of our clients in adapting enterprise software architecture practices to fit within an Agile software delivery approach. In the past year we have seen increased interest in evolutionary enterprise architecture and how service oriented architectures shape the boundaries between enterprise units. The value of an evolutionary approach to enterprise architecture is the creation of lighter weight systems that ease integration between disparate parts. By embracing this approach and the notion of the web as an enterprise application platform, we have reduced overall complexity of application architectures, increased quality and scalability, and reduced development costs.