Industrial/product design is not art, craft or engineering, it has its own purposes, values, measures and procedures. It can be assumed that there is a way of processing research for design as design knowledge is gained through both research and practice. More accurately, design studies could be described as a "field of knowledge", because it is multi-faceted and draws upon many related disciplines. Design, like many other occupations is seeking to establish itself as a profession, it is therefore concerned about the development of a service orientation, the continual growth of knowledge, based on practice and the evolution of a distinct body of knowledge that distinguishes designers from other professionals. Thus design research operates at the interface between academic inquiry and industrial practice, and the creative tension which can emerge from the sometimes differing world views can stimulate the demand for new knowledge generated by research. A primary goal of research has therefore become the examination of how knowledge is accumulated and deployed in the realm of theory and practice.This study established a design research method which began with action research and ended with case study research within the context of design practice, in order to generate a new "field of knowledge". Case study method is a favoured and traditional approach to the study of design practice. The knowledge and understanding is gained from the study of events and processes rather than conjecture. However, such knowledge may not always be useful, as it cannot readily be applied to other cases which might require practical remedies. The use of action research can fill the gap as it is not only focused on an existing process or theory, but also on intended changes or the discovery of new phenomena. The purpose of using this method in design practice is to identify the significant influential factors of a specific design theory/methodology and to show how they affect the implementation of that theory/methodology and individual methodological functions. In this way the design theory/ methodology can provide specific guidance on the conduct of action case research and the knowledge generated can therefore be used within a wide variety of design contexts.Six case study research projects which applied this approach were recorded in the study. A study of existing design theory/methodology was used as a template against which the empirical results of the action case research were compared. A number of scenarios encountered in the use of action case research in the self-conducted setting were presented, to demonstrate the strengths and weakness of the methods. The increasing awareness of practice-based design research as an integral part of professional design practice has been accelerating rapidly in recent years. Designers should therefore recognize the need to extend the base of design knowledge as part of their professional responsibility. Thus, action case study research based on a self-conducted design project can become a vital tool which enables designers to establish a knowledge base for design practice.