SOA Governance - strategic or tactical?

It is both. SOA governance is not much different than any other kind of governance in an organization. Successful SOA governance cannot be achieved without people framework. Socioeconomic factors such as organizational dynamics (I think it is a good synonym for politics) drive the SOA strategy for an organization.This is especially true for IT organizations where the organizations are on the supply side of SOA for their product offerings. Many people miss the fact that the governance efforts are not only limited to the internal employees in an organization but are typically extended to customers and partners. Many organizations co-innovate with customers and partners and these partners and customers significantly influence the SOA governance policies of an organization.

Many architects view SOA governance as a technical challenge, but I beg to defer. Strategic SOA governance is not just a technical problem; it is a business and process problem that has socioeconomic implications. I already talked about the people part. Talking about SOA economics, there is no good way to calculate ROI based on just SOA. Few people have actually tried doing this and I am not sure if this is a right model. Number of services or number of reusable services or any other QoS for SOA don't help to build an economic metrics. SOA is quite intertwined with the business and it is your guess versus mine in extracting a monetary value out of it. Having said this, people do work hard on making a business case for their organizations since SOA is hard to sell.

The strategic to tactical transformation of SOA is not easy. This is where people argue on several reference architectures, policies etc. These are very time consuming and dirty efforts and include several technical, domain, and functional discussions. Cross-functional team works well to tackle this kind of governance problem since it is critical to have a holistic (horizontal) view of SOA with enough help from the experts in several (vertical) areas. SOA architects have to have good people and project management skills since as I already mentioned governance is not just a technical problem. If you are a technical architect, you end up with a diagram like this. This diagram does not help anyone since it mixes a lot of low level details with high level details and the information is difficult to consume. Communicating the architecture is one of the difficult challenges for an architect and it even becomes more difficult if you are describing strategic SOA governance.