Flexibility can be considered as a crucial factor of competitive advantage, especially under conditions of dynamically changing environments. Based on the classical microeconomic definition of flexibility, as introduced by Stigler, and some recent concepts developed in the production economics, this article proposes a primal flexibility measure for multi-product firms. When decomposed, this measure offers useful insights into possible sources of flexibility, especially by investigating the role of both scale and scope economies. This approach provides the theoretical basis to investigate the magnitude and sources of flexibility in the Polish agricultural sector during the transition period.