Practical workflow systems need to be able to tolerate deviations from the initial process model because of un-anticipated situations. They should also be able to accommodate deviations in the format of the forms and data being manipulated. We offer a framework for treating both kinds of deviations uniformly, by applying ideas from programming languages (with workflow agents as potential on-line exception handlers) to workows that have been reified as objects in classes with special attributes. As a result, only a small number of new constructs, which can be applied orthogonally, need to be introduced. Special run-time checks are used to deal with the consequences of permitting deviations from the norm to persist as violations of constraints.

This paper addresses integrity rules that are embedded within engineering design applications and that apply between applications. A representation for integrity rules that are embedded in applications is presented and a set of related methods developed for: (a.) maintaining the integrity condition of application developed data, (b) managing the precedence order between applications, in the context of (c.) changing the schema and the associated mix of applications and (d.) iterated execution of applications and change propagation. Both integrity rules literally embedded within external applications and others required to be embedded within a database are considered. The techniques are demonstrated with an extensive example.

The purpose of this work is to develop automatic methods of semantic integrity maintenance, in support of concurrent engineering. Semantic integrity relations in any final engineering design are built up incrementally, through the use of different computer applications. Here, the structure of these integrity relations are formalized for representation within a database. When changes to a design have to be made, they can invalidate integrity relations in other parts of the design. Formal methods are defined for identifying what data and integrity relations are invalidated by any change. Methods for making changes that minimize re-design are described and formalized. Opportunities for using semantic integrity to assess progress on a design are reviewed.

: One of the primary capabilities for integrated data models and databases for design is support for dynamic evolution. The need is to support design changes that affect the schema, and often existing objects already loaded with data. We present scenarios using EDM-2, a database providing these capabilities. 1. INTRODUCTION: A growing consensus is that the most desirable way to support computer integration in architecture and the construction industry is to rely on a framework supporting a modular, extensible building model [Augenbroe and Rombouts,1994], [Galle,1994]. Application modules represent different knowledge areas: different construction technologies, building types, special building functions or performances, construction planning, or special space uses. The various application modules are assembled and integrated into a building model as needed -- at the beginning of a project, and/or dynamically over the life cycle of the building. Such an approach addresses the combinato...

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The purpose of this work is to develop automatic methods of semantic integrity maintenance, in support of concurrent engineering. Semantic integrity relations in any final engineering design are built up incrementally, through the use of different computer applications. Here, the structure of these integrity relations are formalized for representation within a database. When changes to a design have to be made, they can invalidate integrity relations in other parts of the design. Formal methods are defined for identifying what data and integrity relations are invalidated by any change. Methods for making changes that minimize re-design are described and formalized. Opportunities for using semantic integrity to assess progress on a design are reviewed. Keywords: