Supporting different stakeholder viewpoints across the product lifecycle requires semantic richness to represent product-related information and enable multiview engineering simulations. This paper proposes a multilevel product modeling framework enabling stakeholders to define product models and relate them to physical or simulated instances. The framework is defined within the Model-Driven Architecture using the multilevel (data, model, metamodel) approach. The data level represents real-world products, the model level describes models (product models) of real-world products, and the metamodel level describes models of the product models. The metamodel defined in this paper is specialized from a web ontology language enabling product designers to express the semantics of product models in an engineering-friendly way. The interactions between these three levels are described to show how each level in the framework is used in a product engineering context. A product design scenario and user interface for the product metamodel is provided for further understanding of the framework. Note to Practitioners-The views of stakeholders in a product lifecycle may be different according to their concerns. However, they develop product models and data for a same product. The product models and data should be managed in a single framework to validate consistency of product information. The framework proposed in this paper enables stakeholders to define their product models and relate them to physical or simulated instances. A generic metamodel is also proposed to guide engineers in building their product models using engineer-friendly terms. A product design scenario and user interface prototype was implemented for further understanding of the framework and the metamodel. If the prototype is integrated with a Computer-Aided Design (CAD) system, it can be a powerful mechanism for semantically annotating CAD models.