[en] This paper discusses the concept of a research design model and how it differs from an engineering design model. Essentially, the research design model draws on the methods, materials and processes of engineering design models but more emphasis is placed on conceptualization in 3-D. Typically, equipment and processes in research are unique. Often, there are competing concepts from which to decide. The approach which is evolving at Sandia National Laboratories mixes preliminary, engineering and research design on the same model