Cost is one of the most important criteria for the evaluation of product variants. In this paper, a framework for building systems for cost evaluation of product variants and fabrication plants is presented and discussed. These systems have the purpose of governing the design work towards solutions having an optimal balance between product and production properties. The starting point of the proposed procedure is the cost structure of a manufactured product: the identification of information needed for the evaluation of different product variants, fabrication plants, or both; where the necessary information can be derived from; and how information accessibility and extraction can be supported. The creation of information models for product cost, plant resources, process plans and product geometry is introduced, and the relationships between models are examined, supporting system development. Important guidelines for the creation of a parametric solid model that will serve as the foundation for an automated cost evaluation system are presented.