Abstract: The authors introduce a novel information model for CAD task management, called the task schema, that unifies many of the requisite features for data, process, and methodology management into a single, concise representation. The task schema based approach has been implemented in the Hercules task management system. Unlike previous approaches to task management, in which tasks are defined on demand, or serve as the end representations in and of themselves, Hercules uses a graphical interface to derive tasks from the task schema. Both the task schema and the internal representation of tasks in Hercules have a formal basis in established methods from graph theory and database design. >

Abstract: The Metadatabase project is a multi-year research effort at Rensselaer Polytechnic Institute. Sponsored by industry (ALCOA, DEC, GE, CM, IBM and other) through Rensselaer's Computer Integrated Manufacturing Program, this project seeks to develop novel concepts, methods and techniques for achieving information integration across major functional systems pertaining to computerized manufacturing enterprises. Thus, the metadatabase model emcompasses the generic tasks of heterogeneous, distributed, aand autonomous databases administration, but also includes information resources management and integration of concurrent (functional) systems. The model entails (1) an integrated data and knowledge modeling and representation method; (2) an online kernel (the metadatabase) for information modeling and management; (3) metadatabase assisted global query formulation and processing; (4) a concurrent architectural whereby global synergies are achieved through (distributed) metadata management rather than synchronization of (distributed) database processing; and (5) a theory of information requirements for integration. A metadatabase prototype was recently demonstrated to the industrial sponsors. The basic concept of the metadatabase model is discussed in this paper.

Abstract: This paper develops the data modeling requirements for modeling products, as required for the development of integrated databases in architecture and construction These requirements are then applied to four data models: Entity- Relationship Model, NIAM, IDEF1x and EDM

Abstract: : This paper describes the implementation of a prototype computer program for translating apparel pattern data between different file storage formats. The program demonstrates the feasibility of using a single, standard format as a mechanism for exchanging data between dissimilar pattern design systems. The program is an implementation of an information model previously developed at National Institute of Standards and Technology (NIST) for apparel pattern data. The software was developed as part of an ongoing project at NIST to extend the emerging international standard, Standard for the Exchange of Product Model Data (STEP), to apparel applications. The project is sponsored by the Defense Logistics Agency and the work is being carried out in cooperation with the Computer Integrated Manufacturing committee of the American Apparel Manufacturers Association (AAMA). In the short term, the project goal is to develop a neutral data format for exchanging two-dimensional pattern data between apparel CAD systems. In the longer term the goal is to develop an information model that can be used to encompass the entire apparel life cycle. This achievement would allow all the processes involved in the apparel life cycle to share the same data.

Abstract: The McDonnell Douglas Missile Systems Company guidance software group selected the object-oriented analysis of S. Shlaer and S.J. Mellor (1988, 1989) for engineering the requirements of a mission generation system (MGS). Shlaer-Mellor object-oriented analysis is based on building three types of formal models: information, state and process. The authors focus on the guidance software group's successful adaptation and application of the Shlaer-Mellor method to the mission generation system and compare it with other existing methods, e.g., E. Colbert's object-oriented requirements analysis method (1989). Computer-aided software engineering tool support of this method is examined in relation to the requirements analysis effort. The authors also describe lessons learned during the MGS development. They conclude with a discussion of the issues and observations made by the group in its second object-oriented design application. >

Abstract: Tool Integration Strategies. CAD Framework Integration: A Case Study. Embedded Tool Encapsulation. From Tool Encapsulation to Tool Integration. Design vs. Standards: The Cases. Example Systems. Standardization Concepts in the Nelsis CAD Framework. Data Management Facilities in the AMPLO Design Framework. PACE - A Framework for Electronic Design Automation. Interface Standardization. Definition of Modeling Concepts for a Procedural Interface between VLSI-Design Tools and a Common Database. Testing and Integrating a Federated Electrical Engineering Information Model. Towards a Federated Model of Electrical/Electronic Product Data. SPI: A Procedural Interface for Electronic CAD Tool Integration. Management and Versioning. The Architecture of the Object Management System within the Cadlab Framework. A History Framework for Managing VLSI Design Process. Basic Mechanisms to Support Versioning in the Database Component of a CAD Framework. An Open Configuration Management Model for CAD Frameworks. Inter-tool Communication. A Dynamic Framework for Simulator Tool Integration. Tool Communication in CFI Frameworks. Communicating EDIF Objects: A Standard-Based Approach. Conformance Testing of CAD Interfaces. Impact of VHDL on the Design Environment. VHDL Intermediate Form Standardization: Issues and Status. VHDL Synthesis Based on an FSM Network Model. Version Control in a Constraint-Driven, Object-Oriented VLSI Design Environment. Case Studies. Tight Integration in a Hardware Synthesis System. Introduction of a Framework into a Production IC Design Environment. Lessons Learned from Selecting and Implementing Advanced Systems Engineering Methods and Tools in an Integrated Computerized Environment. Towards an Integrated Environment for Microsystem Design. Object Oriented Data Bases. Do We Need a Common Standard for the Design Structure Model. A Multilayered Data Base System Architecture for Supporting Tool Integration. Support of CAX-Applications by IDM, a Data Model of a Non-Standard Data Base System. Author Index.

Abstract: Large scale information modeling projects, like the development of ISO/STEP, require a modeling approach that a new model not be developed from scratch but to base it on a more generic model which, in its turn, can be based on an even more abstract model, etc. The resulting structure shows a layered framework. On top you will find the most generic concepts and downward the more specific concepts with increased semantics. The benefits of such a model development approach are improvements in: version management, object orientated modeling, concurrent model development, controlled change, standardized interfaces, conformance testing etc. This paper describes an environment which supports the development of a new model out of one or more generic parent models. The generation process consists of two steps. In the first step entities of the parent models can be instanciated while constraining the inherited behavior and introducing new behavior. In fact this process is identical with instanciating run time objects from class templates in the object oriented paradigm. However, in our development environment an important (inherited) property of each entity is selfreproduction. In the second step, therefore, each instance is forced to represent its run time state into some kind of information modeling language specification. Appropriate measures are taken to guarantee that the resulting model will conform the behavior of its parent model(s). The paper will demonstrate this approach in a multi-layered example currently being implemented and will explore several implementation issues.

Abstract: A Graphical Notation Editing System (AGNES) project was initially undertaken in order to resolve some of the traditional problems in textual interfaces as manifested in most database management systems and knowledge base management systems. Entity-Relationship (E-R) Models have provided a popular technique for use in information modeling and analysis [Zhang, 1983]. Although offering a visual model containing a great deal of information in relatively little space, E-R models need to be supported by the necessary graphical tools for accessing and manipulating data. AGNES is an icon based editing tool which provides a graphic user interface between a Database Management System and the user. As the work began, it became immediately apparent that such an interface could also greatly enhance the modeling capability of E-R models. What follows is a set of enhancement tools that can be implemented.

Abstract: Key features from an information model for a computer-aided manufacturing (CAM) database that supports flexible manufacture of printed circuit boards and other selected components and products is presented. This model incorporates information from several sources: shop orders, computer-aided design (CAD), bill of materials, and process setup. The essential activities of manufacturing can be subdivided into several information categories. These categories include products, processes, factory structure, factory operations, and factory inventory. The information model identifies the entities and data elements that are associated with each of these categories, as well as the relationships among the entities. Having provided appropriate levels of abstraction, this model can support a wide variety of products and processes. The resulting relational database implementation is integrated with multiple manufacturing software applications to assist with the operation of a manufacturing facility. >

Abstract: Appropriate design information is critical to the decisions the designer makes in the steps that lead to and in the preparation of design documents. For the inexperienced designer, countless hours may be wasted during the design process searching for information when it is presented in the wrong format. This study defines a practice‐based structural design information model (SDIM) that identifies the key design information elements and documentation required in providing basic structural engineering services. The SDIM was developed through interviews with senior structural engineers in six ENR top 500 design organizations. The objective of the interviews was to identify and document various design information requirements, the form and format in which the information is presented to the user, and the problems faced by the information users during the design process. The results of the interviews were distilled into a descriptive information model that serves as a navigational aid for the young project des...

Abstract: The attainment of high performance is the 'raison d'etre' for doing parallel computation. This means a parallel program is not 'complete' until its performance has been optimized. As it is often unclear how to write a high-performance parallel program, any system for parallel programming must offer support for program performance improvement. Part of such support is the collection, analysis, and presentation of information about program performance. Graphical presentation of information offers insights into the nature of a program's performance that would be difficult, and sometimes impossible, to achieve with a traditional textual view of performance activity. This thesis presents a framework based on a uniform information model for the capture and presentation of parallel and distributed program performance information. The aim is to provide a general programming environment to support application-specific performance analyses and display of performance information for parallel applications. The ideas presented here are realized in chaosMON, a system for the capture and graphical presentation of program performance information. ChaosMON consists of three components that provide support for (i) specification of application-specific performance information of interest to the programmer, (ii) generation of graphical displays for such performance information, and (iii) guidance of performance analysis via an interactive monitor/display interface.

Abstract: The authors investigate the design cycle of large made-to-order products and propose a framework in which the design and engineering of such products may be supported in an integrated manner. The design is modeled as an instance of a kernel design cycle enhanced by design modifiers. A product data model is used to represent the resultant information structure as the design evolves. An assumption-based truth maintenance system captures the design evolution and the dependencies between design actions and the product model. The product information model has levels of abstraction which correspond to the design stages. The design data exchange system described here mainly deals with the representation and management of the design process and the underlying product information model generated through this process. >

Abstract: Presented here is our methodology for developing automated aids for diagnosing faults in complex systems. We have designed these aids as multilevel-multiagent diagnostic aids based on principles that should be generally applicable to any complex system. In this methodology, multilevel'' refers to information models described at successful levels of abstraction that are tied together in such a way that reasoning is directed to the appropriate level as determined by the problem solving requirements. The concept of multiagent'' refers to the method of information processing within the multilevel model network; each model in the network is an independent information processor, i.e., an intelligent agent. 19 refs., 15 figs., 9 tabs.

Abstract: A Graphical Notation Editing System (AGNES) project was initially undertaken in order to resolve some of the traditional problems in textual interfaces as manifested in most database management systems and knowledge base management systems. Entity-Relationship (E-R) Models have provided a popular technique for use in information modeling and analysis [Zhang, 1983]. Although offering a visual model containing a great deal of information in relatively little space, E-R models need to be supported by the necessary graphical tools for accessing and manipulating data. AGNES is an icon based editing tool which provides a graphic user interface between a Database Management System and the user. As the work began, it became immediately apparent that such an interface could also greatly enhance the modeling capability of E-R models. What follows is a set of enhancement tools that can be implemented.

Abstract: It is extremely important for a Flexible Manufacturing System (FMS) to have the ability to recover errors or failures automatically since an FMS is error-prone, and it is usually a complex and large-scale system consisting of multi-cells and multi-stages of work centers. We hereby propose a formal FMS information model and formulate an approach to automatic error-recovery in the FMS based on information sharing among different work stations.

Abstract: : The objective of this program was to conduct a top-level assessment of activity (IDEF-O) and information (IDEF-1x) modeling methods needed to support overarching enterprise framework applications. The results provide a preliminary strategic plan, or blueprint, tailored to the needs related USAF and industry requirements for integrated information modeling capabilities. The plan is a systematic and incremental approach for strategic improvements relative to enterprise framework applications.

Abstract: A database tries to present a faithful model of some body of information we can loosely call "reality" (even though the information might be historical, obsolete, fictional, speculative, or even erroneous). The model is constructed from whatever sorts of materials a particular data model provides, such as relations and attributes, or entities, attributes, and relationships. In this paper, we will build models using the materials provided by functional object models such as Iris [Fi]: objects, types, and functions. Functions collectively model the notions of attributes, relationships, and operations.

Abstract: Exchanging product data between feature-based geometric modelers presents some challenges. This is partly because features technology is still evolving, and also because there are major philosophical differences between the feature concepts on which different systems are based. The Form Feature Information Model (FFIM) that was developed by the pdes committee in the USA and accepted into the International Standards Organisation step standard was tested by means of experiments described in the paper. The modeler used in the experiments was the ASU Features Testbed, which was developed at the Arizona State University, USA, independently of the FFIM. The purpose of the experiments was to identify problems in the FFIM, and to suggest solutions where possible. In addition to the traditional problems of data transfer, such as numerical inaccuracies, a number of other factors that increase the complexity of the feature data-exchange process were identified. Some of these were the lack of relational positioning/locating information, multiple representations of a single feature, representation of certain popular profiles in rather tedious data structures, and the nonunique mapping of features between the two systems. The loss of semantic information, ecapsulated in rules, methods and constraints, seems to place some serious limits on information that can be exchanged with the current version of the FFIM. The pdes/step models are essentially static snapshots that are adequate for exchanging geometric and topological data, but are insufficient for dynamic exchange of feature models that encode engineering semantics in addition to geometric shapes.