Digital Mock-ups (DMUs) are widespread and form a common basis for product description. However, DMUs produced by industrial CAD systems essentially contain geometric models and their exploitation often requires new input data to derive various simulation models. In this work, analysis and reasoning approaches are developed to automatically enrich DMUs with functional and kinematic properties. Indeed, interfaces between components form a key starting point to analyze their behaviours under operational reference states. This is a first stage in a reasoning process to progressively identify mechanical, kinematic as well as functional properties of the components. The overall process relying on the interfaces between components addresses also the emerging needs of conventional representations of components in industrial DMUs. Inferred semantics add up to the pure geometric representation provided by a DMU, to allow for easier exploitation of the model in different phases of a Product Development Process (PDP).