The Generative Structure of Scheme Design Processes

This paper describes the results of investigations and analysis of scheme design activities and proposes the structural model which explains how practical design processes are generated. These investigations have been done with view to know if the systematic design process which proposed from 1968 to 1970 in Japan could be generally applied to practical design activities. Several new facts about practical process were found. First of those facts is that there are various process types in practical design activities, although any proposed process has only one type. The diversity of process suggests the flexiblity of practical design activities. Second is the difference of frequency which each process-unit emerged in practical processes. And in any case the process-unit so called "drawing" is indispensable so that process type 〓IDF〓 becomes the foundamental one which all other types are derived from. Third is the general trend of derivation that with the process division progresses, the lower priority processunit derived except for the "scheduling". And practically the systematic process is vary rare because of having maxium process divisions and always including the exceptional "scheduling". On these facts the derivation model of design process could be built which showed the basic difference between the systematic process and the practical ones and explained the rationality of practical design processes.