Design Of Data Model Research Articles

Municipal GIS and the enterprise data model

Abstract The City of Scarborough, like many corporations, recently re-evaluated its information technology requirements. The decision was made to model the City's needs in terms of activities and data requirements, concentrating on the Municipal Data Model. First, a two year study was undertaken to understand the business activities of all the disparate components that make up the corporation. This study resulted in individual Information Resource Plans (IRP) for each department. A third year was spent in reconciling the many separate documents and creating a high-level Conceptual Data Model for a Corporate Information System. Of the thirteen broad data groupings, four were assigned to the GIS Group for the design of Detailed Data Models and to populate the resultant databases. The GIS Group, in fact, were to initiate the new Information System for the entire City. The modelling sessions involved hundreds of users from the entire user community in small and large groups, in intensive entity-definition act...

Simplified production management software for the small manufacturing firm

Abstract This paper proposes design rules in order to simplify current MRP II software systems and make them suitable for the small manufacturing firm. Simplification rules apply to production data management by reducing database complexity. This has consequences for medium-term requirements planning which is moved toward the realization of simultaneous material and capacity planning. The simplification procedure is completed by applying aggregate decision models to shop floor control which allow the introduction of a minimal transaction processing system. Object-oriented analysis concepts are used for the design of the primary production data model, which has a consistent effect on transaction data and decisional procedures throughout the whole production management software system.

Conceptual modelling of database applications using an extended ER model

In this paper, we motivate and present a data model for conceptual design of structural and behavioural aspects of databases. We follow an object centered design paradigm in the spirit of semantic data models. The specification of structural aspects is divided into modelling of object structures and modelling of data types used for describing object properties. The specification of object structures is based on an E xtended E ntity- R elationship (EER) model. The specification of behavioural aspects is divided into the modelling of admissible database state evolutions by means of temporal integrity constraints and the formulation of database (trans)actions. The central link for integrating these design components is a descriptive logic-based query language for the EER model. The logic part of this language is the basis for static constraints and descriptive action specifications by means of pre- and postconditions. A temporal extension of this logic is the specification language for temporal integrity constraints. We emphasize that the various aspects of a database application are specified using several appropriate, but yet compatible formalisms, which are integrated by a unifying common semantic.

Issues in query model design in object-oriented database systems

The provision of a powerful query system, including a declarative query language and the systems support for efficiently processing queries is essential for the success of object-oriented database technology. Designing a query system involves making a large number of decisions, further complicated by the lack of a universally accepted object-oriented object data model. In this paper, object data model and query model design decisions are enumerated, alternatives are identified, and the tradeoffs are specified.

Cost‐ and Schedule‐Control Integration: Issues and Needs

Cost control and schedule control are two of the most important management functions in the construction industry. Major research efforts are focused on developing procedures for improving the effectiveness of cost and schedule control. As a result, researchers are concerned with the quality, integrity, and timeliness of data that flow through such control systems. A number of data models have been proposed to integrate cost‐ and schedule‐control functions, because such integration is viewed as the, solution to the many problems facing construction projects today. This paper provides an overview of cost‐ and schedule‐control functions, defines the desired control cycle, and discusses the problems and needs of cost‐ and schedule‐control functions. A number of integrated cost‐ and schedule‐control data models, which represent the state of construction research in this area, are discussed. The work‐packaging model is briefly described and is suggested as the most likely existing model to achieve the desired cost and schedule integration. Finally, the conceptual design of a foundational data model for control, based on relational concepts, is provided. The recommended design adopts the conceptual structures of the work‐packaging model.

Object-oriented modelling in digital circuit CAD systems

Many CAD systems involve maintenance of different forms of data for different facets of the design process. This leads to confusion and inconvenience for the designer, and recent research has been directed towards easing this problem by integrating CAD systems around a single central database. However, this approach requires that the different data representations also be integrated, into a single central model that is therefore considerably more complex. This paper formulates such a model for digital circuit design information, representing design data as a complex dynamic structure of entities existing in a four-dimensional space. The model is explained and illustrated with examples from a practical objected-oriented implementation, demonstrating the merits of the object-oriented paradigm for circuit design data modelling.

VLSI integrated circuit design representation in an object-oriented CAD environment

Concepts and some implementation results of a design environment based on an object-oriented design data model are presented in the paper. This model has been used for the definition of the data scheme and the data manipulation language. The former has been defined in terms of VHDL and EDIF mechanisms. Both, the data scheme and the data manipulation language have been implemented in SMALLTALK. Finally, the results of experiments justifying the approach are presented.

Incomplete object—a data model for design and planning applications

Incomplete object—a data model for design and planning applications

Constraint Maintenance as a Data Model Design Criterion

The maintenance cost of database constraints is proposed as a data model design criterion. All previous design criteria are shown to be special cases of constraint maintenance. A human oriented design procedure based on this criterion is developed and shown to be applicable to a variety of data models including relational and functional. Human orientations is achieved by using natural deduction instead of resolution, simple heuristics instead of global optimisation, and a functional notation

Information Engineering and Case: Planning for the Human and Organizational Impact in a Major Systems Development Effort

This paper discusses the impact of nontechnical factors on a major systems development project using new technology. The project used the data focused structured development approach of Information Engineering and the CASE tool Information Engineering Workbench. The project's objectives included transferring the technology skills of this approach to the in-house project team and improving overall data management. The project was to include data modeling, logical and physical database design, prototyping, internal design, and implementation of an application system. Although some important tasks were accomplished, the objective of technology transfer failed. The impact of attempting to introduce a formal, rigorous computerized methodology into an informal systems development organization produced strong resistance from the project team participants. Management's inability to maintain commitment to the new approach, in the absence of a strategic direction, was a contributing factor. Guidelines for addressing nontechnical factors are included.

Designing a property fabric information system for canada lands

The efficient access to and management of approximately 100 000 cadastral survey related records by the Federal Department of Energy, Mines and Resources, Legal Surveys Division, requires the application of GIS and Data Base Management technology. This paper discusses the design process, general specifications, functional requirements, and data model, of a Property Fabric Information System now in development in the Division. This system will be the GIS component of an Automated Canada Lands Information System that the Division will use to manage the majority of its administrative and technical data. The data conversion methodology that will be used to build the databases for this cadastral GIS application, is also outlined.

Towards data modelling in information retrieval

The diffusion of automated information retrieval (IR) ap plications and of applications which share many of the peculiarities of IR applications is increasing. The demand for these types of applications draws attention to the lack of methodologies available for IR data design. The data modell ing of an IR application, that is, the data modelling of the IR part of a complete information system, has not yet been approached and studied as a complete process and in a struc tured way. The first part of this paper introduces the motivations and the scope of the DIRD (Design of Information Retrieval Data) project, which is devoted to the development of an environ ment for the design of advanced applications of IR. The second part of the paper addresses the design of the IR part (or IR application) of an information system. The concep tual paradigm necessary for the design of advanced IR applica tions is investigated. The Entity Relationship (ER) approach is compared with that conceptual modelling paradigm and is examined as a candidate data model for the conceptual design of IR data. A new ER approach is then introduced: this new approach extends the constructs of the ER model to manage the complexity of IR data. Two design examples are given to present the use of the new ER approach in designing IR data.

Proof procedures for detecting redundancy of database constraints

A production-rule-based notation is introduced to express and manipulate database constraints. Two proof procedures are developed to detect the redundancy of database constraints. The direct proof procedure is human oriented and based on natural deduction. Human-oriented proof procedures are important as most data-model design is still done manually and nonredundancy of database constraints is the major determinant of a good design. The indirect proof procedure is machine oriented. It involves conversion of the production rules to the clausal form of first-order logic and resolution theorem proving. Machine-oriented proof procedures are important as many proofs are cumbersome and beyond the time and complexity tolerance of data-model designers. Using the same notation to facilitate both human and machine proof procedures is useful in facilitating human-machine interaction in data-model design. Both procedures are general enough to be used with a variety of data models, including relational and functional models. The applicability of the procedures to a variety of data models is useful in multidatabase environments and in exploring concepts that are common to many data models.

A data model and query language for EXODUS

In this paper, we present the design of the EXTRA data model and the EXCESS query language for the EXODUS extensible database system. The EXTRA data model includes support for complex objects with shared subobjects, a novel mix of object- and value-oriented semantics for data, support for persistent objects of any type in the EXTRA type lattice, and user-defined abstract data types (ADTs). The EXCESS query language provides facilities for querying and updating complex object structures, and it can be extended through the addition of ADT functions and operators, procedures and functions for manipulating EXTRA schema types, and generic set functions EXTRA and EXCESS are intended to serve as a test vehicle for tools developed under the EXODUS extensible database system project.

Functional data model design

A complete algorithm is presented to automate the design of functional data models. The algorithm receives a set of functions and a set of constraints defined on those functions and returns a non-redundant data model with maximal semantic content. The major design criterion of non-redundancy implies that no function in the model should be derivable from the other functions in that model. The minor criterion of maximal semantic content implies that among all equivalent non-redundant data models, the model that exerts maximum control over the behavior of data is the optimum model.

A survey of database management in engineering

Database management in engineering fields is becoming extremely important. A number of reports and papers have been published on this subject and computer-aided design applications. It is important to know state-of-the-art to fully utilize the benefits of this new field. The paper contains a survey of literature on database management for engineering applications. The survey is broadly classified into database management concepts and systems. Research work of various authors in related areas such as database design methodology, data models, data definition and manipulation languages, database integrity and consistency are reviewed. Various database management systems (15 in all) currently in use are reviewed and their features tabulated. Capabilities and usefulness of these systems are provide important developments in data management field to the engineering community. Also, it should be useful to those currently engaged in research on the subject.