Today, during a SOA workshop we had a discussion about governance. Most people see the need for Governance when applying SOA. Without governance your beautiful flexible architecture will soon evolve into SOA spaghetti. Hard to modify, the opposite of business agility.
One goal of SOA governance is that it should verify that Services are reusable: Shared services over specific-purpose implementations.
Governance is usually associated with an enterprise architect role: a boss in charge of architecture. Someone who will police all architectural decision.
This approach to SOA governance is what i would call explicit governance. You explicitly appoint someone to do it. There are other ways of achieving the same goal. You can often design your systems and infrastructure in such a way that it’s only possible to do the right thing. You could call this implicit governance.
An example outside the field of IT: a restaurant has a goal to serve as many customers as possible per table everynight. To achieve this you could ask all the waiters to make sure the customers order fast, and pay fast. In this case the waiters are the police that have to implement to governance. Another way of achieving the same goal would be by having hard uncomfortable chairs, play loud music, and have loud colors in the decoration of the restaurant. In this situation nobody would have to do active governance: customers would just leave soon by themselves.
When doing SOA, you can also implement implicit governance: structure your infrastructure, methodology and organisation in such a way that it becomes really hard to do the wrong thing.
SOA governance will always be a combination of explicit and implicit governance, but i think it’s important to think about ways to do implicit governance.
More on this topic can be found in the design of everyday things: it discusses things like affordances and limitations. How do you design a product in such a way that it can only be used in the way intended? Many of the suggestions in this book can also be applied to the design of IT systems.