2009 IEEE 16th International Conference on Industrial Engineering and Engineering Management, IE and EM 2009, Beijing, 21-23 October 2009 ; Developing product family is one of the most promising approaches in the mass customization paradigm. In the product family perspective, the understanding of product family metrics and modeling is crucial for decision support and analysis. Most of the current product family modeling representation is meant solely for physical product configuration. Therefore, the current product family modeling approaches is not adequate to support various decision making at different product family design issues. An integrated knowledge framework that is able to support decision making in all aspects of interest would be highly desirable. This paper presents a conceptual framework of using semantic annotation for ontology based decision support in product family design. Together with a new commonality analysis based on a semantically annotated product family ontology, the framework illustrates the merits of using semantic annotation in assisting ontology based analysis and decision making in product family design. A case study involving a product family of digital camera is also presented to demonstrate our concepts and approach. ; Department of Industrial and Systems Engineering ; Refereed conference paper