The interoperability among a variety of systems, in or across manufacturing enterprises, has been widely accepted as one of the important factors that affects the efficiency of production. The aim of this study is to deal with the semantic interoperability issues in a product lifecycle management environment. Through the investigation of related works, the need for the formalization of semantic annotation was discovered. This paper addresses this drawback and introduces a framework that uses formalized semantic annotations to assist the knowledge interoperability along a product life cycle.