To measure strategic convergence and related profit erosion are key steps in determining the attractiveness of an industry. The basic assumptions underlying the construction of strategic differentiation indices (SDIs) are analyzed. A systemic approach with epistemological considerations is proposed (1) to categorize and describe product attributes, (2) to build the components of a universal value metric and (3) to construct SDIs. The mathematical model uses the m-dimensional product attribute space and the (n-1)-simplex volume defined by n =m+1 competing products. Average attribute dispersion measures are also used. SDIs performance is exhibited in dynamic, deterministic and Monte-Carlo simulated scenarios.