This paper presents all the required software modules for the user interface of the framework model for the automation of product design processes. The proposed framework model is based on the behavior of human product designer during the design processes of a product and the philosophy of virtual engineering. This paper is a continuation of previous works, that have been done in the area of knowledge engineering and all are based on the philosophy of functional model of human system. This paper concentrates in the main functions of the user interface, which are: Editing facilities for Knowledge base, Editing facilities for Technology base, and the two modules, Behavior module and Protocols modules. The user interface is proposed by studying and analysis of the behavior of the human product designer during the design of a new product. Also an architecture for expert system proposed for the engineering domain to be used for automation product design processes.