This paper presents ongoing work dealing with design by features using the constraint satisfaction approach. Basic ideas related to the unified definiton of features and constraints from an ontological point of view are clarified. Requirements for defining and administering constraints in feature-based models are presented and an architecture for consistency mangagement in feature-based design is proposed. The two main modules of interest are the feature-based design module and the consistency management module. The first module is tntended to support the design of product parts by creating and manipulating feature support the design of product parts by creating and manipulating feature primitives that possess design semantics. The second m...