Product definition on the basis of STEP IPIM, ISO 10303 product model standard grounded a new technology in engineering. One of the main trends in product modeling is improving communication between human and modeling procedure by including intelligent computing methods both in modeling procedures and model descriptions. This is a great challenge because definition of product objects must be transparent for engineers at any time in an industrial engineering process. In this chapter, the authors introduce one of their contributions in knowledge assisted intelligent control of engineering object definition at product model based engineering activities. The proposed modeling is devoted as an extension to currently prevailing product modeling in leading product life cycle management systems. Chapter starts with an introduction to the proposed modeling by its preliminaries in work of the authors and others. As the main contribution, transferring knowledge from the human product definition process to the product model, method for better communication at object definition, new content definition for engineering objects, and multilevel structure in order to facilitate implementation are discussed. In the main methodology of the proposed modeling contextual human intent, engineering object, and decision entities are applied in the form of spaces extending the conventional model space in product models.