Product Lifecycle Management (PLM) has been considered as an essential con-cept for improving the product competitive ability in manufacturing enterprises. The PLM solution aims at providing a shared platform for facilitating the man-agement of the knowledge related to any product development process in or across enterprises. However, facing with different standards, enterprise systems and stakeholders, enterprises still need to deal with interoperability issues be-tween those collaborative information systems, encompassing their capability to find the right information during the whole Product Life Cycle (PLC). The objec-tive of this paper is to cope with the major issue of semantic interoperability, by proposing a formalization of semantic annotations and a prototype for facilitating a coherent, complete and contextualized interoperability of knowledge between all enterprise systems and related stakeholders. An example of the instantiation of our method within a real application scenario in manufacturing domain is present-ed to demonstrate its applicability and use, both at the engineering and the exploi-tation phases.