One of the key things I saw in 2008 was the rise of events and eventing through Event Driven Architecture (EDA). While "events" have always existed, they have primarily been used in specific markets such as algorithmic trading where our Apama product is commonly used. The shift in 2008, and moving forward, was that events became more mainstream and that meant that the business and their technical developers were looking to see how they could harness events.
In contrast to traditional SOA infrastructure that use service orchestration such as BPEL to control all aspects of the flow, event based architectures can be used to implicitly enable process to occur. An event typically happens on a state change or document passing between organizational boundaries or similar. In order for the event to be useful, it needs to be published to everyone who could possibly be interested and as such, an event consumer can correlate multiple event instances to define new logic and/or to monitor the business event in action. The key benefit for the enterprise is that the events and their correlation do not have to occur at the initial development time, they need to be captured in a single flow. Handling business events in this way allows a much more organic growth to the logic to be implemented.
Now, any changes in practice will always create new challenges you will need to overcome, not least of which will be the ability for people to assume that business will implicitly happen when there is no end-to-end picture, such as what people expect from BPEL or UML. With guidance, we can overcome these issues because typically the number of processes that are discretely modeled within an organization are few. One of the key things that has to happen is the idea of event modeling. While there are elements of this in UML through state change diagrams, other tools may have to be used. Another thing to consider here is that the dynamic aspects of the business will need to be captured and displayed in real-time to allow business decisions to occur when an event really occurs rather than hours or days later.
In these challenging and opportunistic times that currently exist, I see the arrival of event based architecture as arriving in the mainstream at a very convenient time. Businesses are restructuring through mergers and acquisitions, so IT professionals need to be able to satisfy this change, plus forces in our market are causing new approaches to be taken, including the idea of clouds that become more than mere hosting platforms.
SOA What? I too agree with Dan Foody that the conventional SOA is not dead by any means. It will actually continue to grow and serve more needs. However, I believe you will see that EDAs will rapidly augment existing projects to initially provide real time visibility and then gradually it will help lift some of the burden on the business as your EDAs evolve and grow. When that happens, you will start to see more business users being able to implement business logic in real-time rather than having to go back to IT.