In my last post (Three major foundations for SOA) I tried to focus on semantic (especially in the business and information domains) as an important aspect of SOA adoption. This post is a bout the advantage of formal semantic and how to start with formal semantic. Semantic can be formal and informal. Formal semantics are definitions that people can understand; informal semantics are definitions that machines can process. In most of the cases when we mention semantics we mean the informal semantics. But when we dealing with enterprise architecture (to accelerate SOA adoption) it’s better to use formal semantics. Formal semantic are expressed by language such as RDL and OWL, which are based on XML (OWL and RDL actually define the semantic web). There are two advantages for using formal semantic: 1) it enforces you to be more precise with your definitions. 2) it enable verification and consistency checking. I won’t explain formal semantic in this post but I’ll suggest how to start: 1) On the BPX e-learning page there is a great Introduction to Semantics that you should Start with: Three major foundations for SOA 2) After having general idea about semantic web I suggest trying and experiencing it. To do so you should download Protege – a free semantic web editor ( http://protege.stanford.edu/download/download.html ) and the Protégé-OWL Tutorial ( http://www.co-ode.org/resources/tutorials/ProtegeOWLTutorial.pdf ) 3) Follow the Tutorial and learn by experience how to build ontology. 4) After having enough knowledge I would suggest you to start and build your own ontology for your own enterprise needs.