ABSTRACT

For example, high performance CAD systems are probably furthest developed in building construction in the areas of prefabricated construction and piping. Early work in systems building in England led to the development of such systems as CEDAR and OXSYS systems and powerful CAD systems were developed to support them (for a survey, see Eastman, 1992a). With the abandonment of industrialized construction of hospitals, these CAD systems became irrelevant (though some were adapted to become object-based CAD systems, where the components and rules had to be entered by the user). Integrated piping design packages are available from such firms as Computervision and Intergraph that support design at various levels of abstraction, integrate various analyses packages, and develop bills of materials for construction. The PDMS backend database for piping design also has its adherents. In both of these areas, the elements to be composed could be defined, the performances and rules of composition were fixed. In areas outside of construction, similar conditions exist; electronic design has proceeded far because the three conditions could be fixed. Manufacturing has proceeded more slowly because the above structure was more difficult to define.