No abstract

In this paper we present an overview of principles and mechanisms which support management in their task to control and track the engineers work and which guide engineers through the creative design stage. In today's engineering environment'> engineers use design tools to create, modify and verify their designs. During this work the primary focus of an engineer is to successfully perform design tasks. Design descriptions and the tools that operate on them become more complex every day. Today design descriptions are usually constructed hierarchically, consist of multiple levels of abstraction (views) and have a status. The central theme in our approach is that the framework maintains information about the design descriptions and the design activities, so called meta data. This involves primarily information on the presence of cells, or design objects, their relationships, their version history, and the operations that have been performed on them. The information model we use is the OTO-D data model. It is particulary suited to visualize object type hierarchies.The principles and mechanisms are implemented in a set of framework services which are part of the Nelsis Framework. The Nelsis CAD Framework User Services allow engineers to interact with the framework, for instance to invoke tools or to browse information stored by the framework. The services include a hierarchy browser, a version browser, a design flow browser, and more.