Platform-based product development depends on many factors, including technology, cost, competition, and life cycle considerations. Many companies would benefit from knowing more about the nature of their product families and how they impact platform-based product development. We assert that the development of a product platform and its derivative family of products is also impacted by the homogenous or heterogeneous nature of the products being developed, which has received little attention in previous engineering literature. The current study introduces an original metric for assessing the degree of homogeneity or heterogeneity in a given family: the homogeneity versus heterogeneity ratio (HHR), which works at two levels of abstraction, namely, family and function. This study focuses on the platform leveraging strategy and takes into consideration two other aspects of platform development: the specification of the family and the necessity of differentiation. To support platform design, the HHR family and HHR function metrics quantify the ratio of homogeneity to heterogeneity in the family to recommend a platform leveraging strategy by highlighting homogeneous functions that support platform leveraging. Reverse engineering helps us to retroactively study three types of families (power tools, single-use cameras, and blue jeans) using HHR family and HHR function . In particular, we demonstrate: (1) quantification of the homogeneity/heterogeneity of a family of products based on their functions; (2) recommendation of a leveraging strategy based on HHR;(3) a new leveraging strategy, the combined leveraging strategy via cross leveraging; (4) how HHR can help designers to validate the product family specification; and (5) how HHR can highlight needs to differentiate a family of products other than through functions.