Nowadays, the need for systems interoperability in or across enterprises has become more and more ubiquitous. Many research works have been carried out in the fields of information exchange, transformation, discovery and reuse. One of the main challenges in these researches is to overcome the semantic heterogeneity between enterprise applications along the life cycle of a product. As a possible solution to assist the semantic interoperability, the semantic annotation has gained many attentions and widely used in different domains. We collect a number of literature that applied semantic annotations on different objects, and classify them according to the subject being described in an enterprise architecture framework. In this paper, a detailed survey, especially from the formalization perspective, is presented to identify the existing drawbacks and to point out the possible research directions.