A framework for the analysis and evaluation of enterprise models

Bibliography: leaves 264-288.The purpose of this study is the development and validation of a comprehensive framework for the analysis and evaluation of enterprise models. The study starts with an extensive literature review of modelling concepts and an overview of the various reference disciplines concerned with enterprise modelling. This overview is more extensive than usual in order to accommodate readers from different backgrounds. The proposed framework is based on the distinction between the syntactic, semantic and pragmatic model aspects and populated with evaluation criteria drawn from an extensive literature survey. In order to operationalize and empirically validate the framework, an exhaustive survey of enterprise models was conducted. From this survey, an XML database of more than twenty relatively large, publicly available enterprise models was constructed. A strong emphasis was placed on the interdisciplinary nature of this database and models were drawn from ontology research, linguistics, analysis patterns as well as the traditional fields of data modelling, data warehousing and enterprise systems. The resultant database forms the test bed for the detailed framework-based analysis and its public availability should constitute a useful contribution to the modelling research community. The bulk of the research is dedicated to implementing and validating specific analysis techniques to quantify the various model evaluation criteria of the framework. The aim for each of the analysis techniques is that it can, where possible, be automated and generalised to other modelling domains. The syntactic measures and analysis techniques originate largely from the disciplines of systems engineering, graph theory and computer science. Various metrics to measure model hierarchy, architecture and complexity are tested and discussed. It is found that many are not particularly useful or valid for enterprise models. Hence some new measures are proposed to assist with model visualization and an original "model signature" consisting of three key metrics is proposed.Perhaps the most significant contribution ofthe research lies in the development and validation of a significant number of semantic analysis techniques, drawing heavily on current developments in lexicography, linguistics and ontology research. Some novel and interesting techniques are proposed to measure, inter alia, domain coverage, model genericity, quality of documentation, perspicuity and model similarity. Especially model similarity is explored in depth by means of various similarity and clustering algorithms as well as ways to visualize the similarity between models. Finally, a number of pragmatic analyses techniques are applied to the models. These include face validity, degree of use, authority of model author, availability, cost, flexibility, adaptability, model currency, maturity and degree of support. This analysis relies mostly on the searching for and ranking of certain specific information details, often involving a degree of subjective interpretation, although more specific quantitative procedures are suggested for some of the criteria. To aid future researchers, a separate chapter lists some promising analysis techniques that were investigated but found to be problematic from methodological perspective. More interestingly, this chapter also presents a very strong conceptual case on how the proposed framework and the analysis techniques associated vrith its various criteria can be applied to many other information systems research areas. The case is presented on the grounds of the underlying isomorphism between the various research areas and illustrated by suggesting the application of the framework to evaluate web sites, algorithms, software applications, programming languages, system development methodologies and user interfaces

Structural Stability Research Council: Proceedings 1982

One of the purposes of the the of Council is to maintain a forum where the the of Council is to maintain a forum where the structural stability aspects of metal andcomposite metal and concrete structures and and their components can be presented for evaluation, and pertinent structural research problems proposed for investigation. The Annual Technical Session provides an opportunity to carry out this function

Aeronautical engineering: A continuing bibliography with indexes (supplement 189)

This bibliography lists 579 reports, articles and other documents introduced into the NASA scientific and technical information system in June 1985

Human amblyopia and its perceptual consequences

The presence of ocular defects of an optical or muscular nature during early childhood can cause amblyopia: a reduction in visual acuity of the defective eye. The research reported in this thesis investigated the impact of amblyopia on some aspects of visual perception by evaluating three main perceptual functions: precision of judgement of spatial relationships (in three-dimensional space), ability to detect depth in tests of stereopsis, and contrast sensitivity. In some experiments amblyopic subjects were paired with non-amblyopic subjects who had monocular acuity deficits owing to uncorrected refractive errors, in order to assess the importance of the acuity deficit as a determinant of other perceptual losses suffered by amblyopes. In an alignment task non-amblyopes with monocularly reduced acuity performed significantly better than amblyopes, suggesting that the acuity deficit was not solely responsible for amblyopes' perceptual deficit in this task. However, in another experiment in which a greater variety of spatial cues was provided amblyopes performed as well as non- amblyopes. Thus their perceptual skills would seem to be adequate for efficient functioning in most normal environments where spatial cues are abundant. Previous reports that amblyopes generally lack stereopsis were confirmed in two experiments with a few interesting exceptions, whose cases are discussed. The data obtained in the four experiments on space perception and stereopsis in amblyopia provided support for most current theories in these areas. Experiments on contrast sensitivity showed that the losses suffered by amblyopes, as measured by interocular comparison, varied between individuals, both in depth and in bandwidth (the range of spatial frequencies affected). This variation was not directly related to the extent of acuity deficit, or to the condition which originally gave rise to amblyopia, but did seem connected with the age at which the subject first received treatment for the primary causative ocular defect. A similarity between the contrast sensitivity functions of amblyopic eyes and those of infant eyes is considered as a basis for explaining the nature of contrast sensitivity loss in amblyopia. Some preliminary attempts to measure contrast sensitivity in infancy by methods suitable for screening purposes are described in the final chapter. The thesis includes a historical review of theories of amblyopia derived from clinical and experimental work on human subjects, and a critical evaluation of experimental work in which animals were visually deprived with a view to measuring the contributions of experience to visual development. The claims of some authors that such work may have clinical relevance for preventing or treating amblyopia are refuted, since clinical experience has already furnished sufficient evidence to achieve these ends. The perceptual consequences of human amblyopia, as characterised in the present research have important practical implications for the amblyope, and important theoretical implications for models and mechanisms of visual perception and its development

An approach to enacting business process models in support of the life cycle of integrated manufacturing systems

The complexity of enterprise engineering processes requires the application of reference architectures as means of guiding the achievement of an adequate level of business integration. This research aims to address important aspects of this requirement by associating the formalism of reference architectures to various life cycle phases of integrating manufacturing systems (IMS) and enabling their use in addressing contemporary system engineering issues. In pursuit of this aim, the following research activities were carried out: (1) to devise a framework which supports key phases of the IMS life cycle and (2) to populate part of this framework with an initial combination of architectures which can be encapsulated into a computer-aided systems engineering environment. This has led to the creation of a workbench capable of providing support for modelling, analysis, simulation, rapid-prototyping, configuration and run-time operation of an IMS, based on a consistent set of models associated with the engineering processes involved. The research effort concentrated on selecting and investigating the use of appropriate formalisms which underpin a selection of architectures and tools (i. e. CIM-OSA, Petrinets, object-oriented methods and CIM-BIOSYS), this by designing, implementing, applying and testing the workbench. The main contribution of this research is to demonstrate that it is possible to retain an adequate level of formalism, via computational structures and models, which extend through the IMS life cycle from a conceptual description of the system through to actions that the system performs when operating. The underlying methodology which supported this contribution is based on enacting models of system behaviour which encode important coordination aspects of manufacturing systems. The strategy for demonstrating the incorporation of formalism to the IMS life cycle was to enable the aggregation into a workbench of knowledge of 'what' the system is expected to achieve (i. e. 'problems' to be addressed) and 'how' the system can achieve it (i. e possible 'solutions'). Within the workbench, such a knowledge is represented through an amalgamation of business process modelling and object-oriented modelling approaches which, when adequately manipulated, can lead to business integration

The suitabilty of conceptual graphs in strategic management accountancy

The hypothesis of the research is "conceptual graphs are a suitable knowledge-base decision support tool for use by managemenat ccountants in strategic planning", explained as follows. Knowledge-based approaches can help accountants apply their skills in the direction of strategic management problems. Such problem domains cannot be modelled effectively by computer alone, hence we are only interested in those advanced knowledge-based methodologies that can be adequately reviewed by strategic management accountants in the light of their own continually changing tacit and implicit knowledge. Structured diagram techniques, such as flowcharting, are well known by accountants and are a clearly understandable yet important aid in problem review. Apart from being founded on a logically complete reasoning system, the knowledge-based methodology of conceptual graphs was formulated to be an enhancement of these other methods. Furthermore the graphical form of conceptual graphs enjoy an apparent similarity to the 'negating' brackets in the accountant's traditional bookkeeping model. After conducting a comparative study with two similar methodologies in current use showing the technical advantages of conceptual graphs, the Conceptual Analysis and Review Environment computer software was devised and implemented. CARE was used to test the - accepted graphical form of conceptual graphs through a series of user evaluation sessions. The evaluations started out with subjects from the conceptual graphs community itself, then key business school staff, and culminated in a session with senior practising accountants. In addition, CARE was enhanced iteratively in accordance with the results of each evaluation session. Despite their strong prima facie attractiveness and positive response from the conceptual graphs community session, as the user evaluations progressed it became increasingly evident that the inherent complexity of conceptual graphs fundamentally undern-tined them as a viable tool, other than for very trivial problems well below the level needed to be viable for strategic management accountancy. Therefore the original contribution of this research is that its hypothesis turns out to be false