Design capability is the most important factor explaining the success of a company in international markets. Despite its importance of design capabilities and many researches in this field, it seems that a precise conceptualization of the relationship between mastering product technologies and improving the level of design capabilities in an enterprise has not yet been done. In this article, while separating product technology from process technology, a framework for operationalizing the concept of design capability is provided. The validity of this framework has been evaluated using the focus group method. Also, using the proposed framework, the process of formation and growth of design capability and its relationship with acquiring product technologies has been explained through a case study of 230–320 MVA Generators in MAPNA Industrial Group.