Family generation in integrated engineering systems

Abstract

Design is a process of defining components. Defining components here means identifying component entities in the context of related entities and determing their detailed specifications. The former may be called structure design and the latter parameter design. Components are usually hierarchically structured with the product at the highest level and the atomic components at the lowest level. Since the design proceeds in a top-down fashion, entities are registered and attribute values are stored explosively in accordance with the progress of design activities in a databased CAD environment. Structure design has been automated little. It may be said that the major job for a designer is to register components in a CAD system. In modern industry, however, components are standardized extensively. Thus, the designer has to use information of fixed relationships among standized components. Family generation supports the structure design of various design activities. It provides the tools for defining component hierarchies as family catalogues in a standard database and the tools for generating components in so-called project databases by maintaining family member relationships. Users can add and modify the standard components easily through the problem-oriented user language interface. This function should be indispensable in realizing a sophisticated integrated engineering system. It also can respond to the salesman's requirement for a prompt and consistent preliminary estimation of complex products such as chemical plants and buildings. The family generation function is designed to utilize the following features of a CAD environment: