Data Base Requirements for Concurrent Design Systems

The data base requirements for concurrent design systems are discussed. An object-oriented data base, which allows for definition of complex objects, specification of relationships between objects, and modular expandability without affecting the existing information is defined. The data base is developed based on the object-oriented data model implemented in Smalltalk-80. An assumption-based truth maintenance system for maintaining the dependency relationships between design and manufacturing information is described.

Adding Prolog Rules and OOPs Inheritance to Legacy Databases

We present a viable approach to add rules capability or object orientation to legacy databases. Using a combination of language compilation, run-time trigger mechanisms and inter-language call facility, we integrate an object-oriented logic programming language, called OOLP, with an existing CIM Database System Product, IBM’s CIM CDF. The result is a system that provides storage management of complex objects, rule-based validation, object oriented knowledge modelling and declarative query capability.

Designing an Engineering Database for Telephone Networks

An engineering database modeling telephone outside plant networks is developed. Semantic and relational database design methodologies are used with the semantic data model developed based on an extended entity-relationship approach. This logical model is used to generate a normalized relational data structure. This database holds engineering data supporting engineering analyses, engineering work order generation procedures, and network planning activities. The database has been linked to separate network analysis programs and CAD-based network maps by a database application.

On Object-Oriented Databases, Materialized Views, and Concurrent Engineering

Concurrent engineering seeks to reduce the length of the design life cycle by allowing multiple engineers to work on a design concurrently using their different design tools. A major stumbling block in achieving this goal is that most design tools use different file formats. Emerging standards such as STEP/PDES/EXPRESS reduce this barrier, but conformance to standards is not enough. One reason design tools have different file formats is because each tool requires a different perspective or view of the design. Engineering databases must provide designers with the ability to define application specific views of design data, and the ability to propagate changes among those related views. In this paper, we examine how an object-oriented database system can support the definition of application views using a class hierarchy and multiple inheritance.

CIM Dictionaries: An Evolutionary Approach to CIM Data Integration

This paper provides an overview of methods and ideas to achieve data integration in CIM. It describes a dictionary approach allowing participating applications to define their common constructs gradually as an additional service across application systems. Because of the importance of product definition data, the role of PDES/STEP as part of this dictionary approach is also described. The technical concepts of the dictionary, such as schema mapping, semantic data model, user methods and the required additions within participating applications are explained. Problems related to data integrity, data redundancy, performance and binding of dissimilar software components are discussed as well as the deficiencies related to today’s data modelling capabilities. The added value an active dictionary can provide to a CIM environment consisting of established applications in heterogeneous environments, where migration into one standardized homogeneous set of CIM applications is not likely, is also explained.

Case Study Approach for Information-Integration of Material Handling

Information-Integration is vital for keeping manufacturing operations competitive. A case study approach has been adopted to better understand the role of information in integrated manufacturing. Information is now considered a corporate asset. Creation, processing, movement, and security of information is therefore as important as that of the products/services of an enterprise. The case studies have helped in identifying the issues involved in developing an information system and supporting software framework for a manufacturing enterprise. The case studies have helped in refining an integration model, and identifying the characteristics desirable in modeling methodologies and tools. This paper describes a case study dealing with integrated manufacture of optical fiber products. A phased development and implementation approach was adopted where a small, manageable slice of the system is considered for the case study followed by functional modeling (IDEF0) and data flow modeling (Data Flow Diagrams). This identifies the pieces of information of interest. The information relationships are modeled using Extended Entity Relationship (EER) diagrams which are then mapped on to a relational model. The relational tables thus obtained were implemented on a commercial Database Management System. The functional constraints and application interfaces were then built using SQL and commercial application interface tools. The sections in the paper describe the functional models, data flow diagrams, EER diagrams, relational database design, and user/application interfaces developed for the system. Implementation experiences and observations are discussed followed by plans for the next phase of the system.

A Technological Data Base in Aircraft Production Environment

In a factory, where many cells work togheter, we obviously have a significant proliferation of data and information concerning the production flow. We have, of course, to control this event in order to avoid dramatic consequences, as incoherence, disalignment and data inconsistency. On the other hand, we have to notice thatt data production is generated by many different applications, and by many people having different skills and responsibilities, and using different applications and technologies. Trying to solve this problem, we decided to define an unique and solid data base structure at factory level, called Technological Data Base (TDB), in which all users (man or application) generating information, useful to production activities, must store data under their own responsibility. Data stored in this Data Base are defined as “Consolidated”, to indicate data that are released by an application process and are used as an input or a trigger for another application process. These consolidated data can be: - Structured data, i.e. data that can be organized in fields or attributes, mainly coming from Planning Applications. - Unstructured data, i.e. data that are stored in the Data Base as a bits sequence, mainly coming from CAD/CAM applications managed as a black-box by the DBMS, while specific applications (at cell level) provide to understand them. This Technological Data Base is an object-oriented Data Base, where functions are implemented in order to store, manage, and distribute all multi-media information requested to drive and control the different plant work-centers. A pilot application of this TDB is already working in Alenia-Pomigliano factory — in a conventional workshop environment, and it will be extended to the other factories in an automated environment.

A Multimedia Concept Database for Improved Life Cycle Design

The architecture of a multimedia conceptual design aid, the Concept Database, is presented. The goal of the Concept Database is to provide design teams with easy access to information about life cycle design issues for competing design concepts and access to relevant past designs. The architecture builds on our previous experience in developing the multimedia design archival system called Design SCRIBE (Structured Capture and Retrieval Information Base for Engineering Design.) Approaches to selectively retrieving descriptions of design concepts and past designs are summarized.

Product Data Management and Supporting Infrastructure for an Enterprise

Global competition challenges engineering and manufacturing enterprises to shorten product development cycles, while meeting more stringent quality and cost objectives. In addition, product design and manufacturing methodologies are more complex, encompassing a complicated integration of electronic, mechanical, optical, and other subsystems.

Using Information Theory to Model Design Processes Supported by Information Systems

This paper describes the use of information theory to model the interactions between various design agents in a design/manufacturing organization. In typical multidisciplinary design environments, the design attribute space is constrained by the requirements and compatibility conditions introduced by interacting disciplines. A key factor toward efficient design lies in the recognition of this constrained design space, and in communicating this to the designers during the initial stages of the design process. As a result, engineering information systems that support the multidisciplinary design activities must incorporate these constraints, and provide designers with a uniform mechanism that will assist design attribute awareness, provide decision discriminators and model design attribute dependencies. The concept of entropy as defined in information theory will be used to quantify both the information content of a design as well as the design attribute space. Specifically, we shall investigate how this model may be used for a class of parametric design problems.