Products continuously change over time to satisfy new customer needs and technologies, and proper prediction of future products can play an important role in business success. Thus, understanding structural and functional changes in previous products is essential to identify their evolutionary patterns, which then can be used to develop new ones. Noting the significance of evolution in a product family, this research aims to characterize and extract underlying properties of the evolution process. In the presented work, static network analysis is used to investigate topological changes in a product family network over time. Three steps are proposed to effectively capture the evolutionary properties of a product family. First, the network representation of a product family is defined. Second, product family networks in different time periods are quantified through network measures. Finally, patterns in the network measures are analyzed to extract common evolutionary characteristics. The methodology proposed in this study would serve as a foundation for the analysis of product family evolution, and is expected to help derive the future configuration of a product family.