Understanding how and where SOA Governance and API Management converge is as important as understanding each separately. Although this book defines API Management as an extension of SOA Governance, the truth is that the former takes taking SOA Governance to a completely different level. APIs have become the default mechanism to expose business functionality and information assets, not only to mobile apps and web applications but also to business partners and even things (any devices such as watches, TVs, and so on). With different renowned analysts concurring in their prediction that by 2020 there will be some 26 billion connected devices and at least 6 billion smartphones, it doesn't require a mathematician to estimate that the number of APIs to be built will grow almost at the same pace.

Having said that, it is also natural that to expect that disciplines such as API Management and SOA Governance, rather than evolving separately, will converge and eventually evolve as a single discipline. We are already seeing evidence of this. Many product vendors (including Oracle) have adapted (or are adapting) their SOA offerings to provide full support for API development and API Management. However, this evolution has only just started in recent years and more changes are expected to come.

The following diagram aims to provide a view of where both disciplines differ and converge:

As can be seen from the diagram, the convergence of SOA Governance and API Management gives birth to a new discipline known as Application Services Governance (ASG). The objectives of ASG are visible in the center, where SOA Governance and API Management overlap.