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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Empirical comparisons of system analysis modeling techniques

Gemino, Andrew C. 11 1900 (has links)
The development of information systems consumes an increasing share of economic resources. Over a trillion dollars worldwide is invested in information technology annually, and this investment is growing over $100 billion a year. This investment occurs despite failure rates for large information system development projects that are estimated as high as 75%. The large investment and high failure rates combine to create the potential for significant impact from information system development practices that are able to address these failure rates. Researchers, over the past thirty years, have studied factors that drive these high failure rates. One of the factors repeatedly mentioned in practitioner surveys is the importance of accurate communication in the "upstream" analysis and planning stage of a project. System development professionals are aided in their upstream planning through the use of information system development methods (ISDM's). ISDM's are modeling tools and techniques that are capable of representing information about an information system. Many alternative system analysis modeling techniques have been developed, yet few empirical comparisons of the alternative techniques have been completed. The lack of comparative empirical data has contributed to a proliferation of modeling methods and increased the confusion surrounding the adoption of system analysis methods by system development professionals and teachers. This study addresses the issue of empirical comparison of system analysis modeling techniques. A new instrument and empirical method is proposed for developing a comparison of the level of "understanding" that a participant is able to create by viewing a description of a particular domain. The level of "understanding" is addressed using three measures: comprehension, problem solving, and text reconstruction. The new measures of "problem solving", suggested by Mayer in the field of Education Psychology, and "text reconstruction" or "Cloze", suggested by Taylor in the field of Communications, extend empirical instruments previously used by system analysis researchers. To test the efficacy of the proposed instrument and method, two empirical studies were developed in this thesis. The first study used the new instrument to compare three development methods "grammars: Text descriptions; Structured Analysis (using Data Flow Diagrams and Entity Relationship Diagrams); and Object Oriented Diagrams. The study was labeled an "Intergrammar" comparison, as three grammars representing three fundamental approaches to developing an analysis model were compared. Two propositions, in regards to the intergrammar study, were tested. The first suggested that viewing descriptions created with diagrams would lead to a higher level of understanding than viewing a description based solely on text. This hypothesis was confirmed. The second hypothesis suggested that viewing a domain description created using an object oriented grammar would lead to a higher level of "understanding" than viewing a description created using the "Structured Analysis" approach. The results confirmed the hypothesis that the group of participants using the Object-Oriented grammar scored higher in "understanding" than participants using the Structured Analysis grammar. A follow-up protocol analysis was undertaken to illuminate why the participants using object methods scored. The analysis of these protocols indicated two things. First, participants using Structured Analysis made little use of the Entity Relationship Diagram (ERD). Second, participants seemed to favor the "object" concept when answering questions. These findings provide some empirical evidence that objects may be more "natural" cognitive constructs than those used in Structured Analysis. The second study revisited a study Bodart and Weber's study regarding alternative grammars for the Entity Relationship Diagram. A grammar using mandatory attributes and relationships with sub types, the other using optional attributes and relationships, were compared. The grammars shared a common primary grammar, therefore, the second study was labeled an "Intragrammar" comparison. The new instrument was again used in this study. The ontological constructs proposed in the Bunge-Wand-Weber (BWW) model were used to suggest the theoretical advantage of the grammar using mandatory attributes and relationships with subtypes. The results supported the theoretical advantage associated with mandatory attributes and relationships with subtypes. This intragammar study provided further evidence of the utility of the empirical instrument proposed in this thesis. This study has implications for future empirical research in system analysis. The empirical instrument described in this thesis extends previous empirical research instruments with the introduction of the problem solving and the Cloze task. In two studies, the new instrument has displayed the sensitivity to differentiate between treatment groups. The results from the two empirical studies suggest that object-oriented analysis may hold advantages over traditional structured analysis, and that mandatory attributes and relationships may be preferred to optional attributes and relationships in the entity relationship grammar.
2

Empirical comparisons of system analysis modeling techniques

Gemino, Andrew C. 11 1900 (has links)
The development of information systems consumes an increasing share of economic resources. Over a trillion dollars worldwide is invested in information technology annually, and this investment is growing over $100 billion a year. This investment occurs despite failure rates for large information system development projects that are estimated as high as 75%. The large investment and high failure rates combine to create the potential for significant impact from information system development practices that are able to address these failure rates. Researchers, over the past thirty years, have studied factors that drive these high failure rates. One of the factors repeatedly mentioned in practitioner surveys is the importance of accurate communication in the "upstream" analysis and planning stage of a project. System development professionals are aided in their upstream planning through the use of information system development methods (ISDM's). ISDM's are modeling tools and techniques that are capable of representing information about an information system. Many alternative system analysis modeling techniques have been developed, yet few empirical comparisons of the alternative techniques have been completed. The lack of comparative empirical data has contributed to a proliferation of modeling methods and increased the confusion surrounding the adoption of system analysis methods by system development professionals and teachers. This study addresses the issue of empirical comparison of system analysis modeling techniques. A new instrument and empirical method is proposed for developing a comparison of the level of "understanding" that a participant is able to create by viewing a description of a particular domain. The level of "understanding" is addressed using three measures: comprehension, problem solving, and text reconstruction. The new measures of "problem solving", suggested by Mayer in the field of Education Psychology, and "text reconstruction" or "Cloze", suggested by Taylor in the field of Communications, extend empirical instruments previously used by system analysis researchers. To test the efficacy of the proposed instrument and method, two empirical studies were developed in this thesis. The first study used the new instrument to compare three development methods "grammars: Text descriptions; Structured Analysis (using Data Flow Diagrams and Entity Relationship Diagrams); and Object Oriented Diagrams. The study was labeled an "Intergrammar" comparison, as three grammars representing three fundamental approaches to developing an analysis model were compared. Two propositions, in regards to the intergrammar study, were tested. The first suggested that viewing descriptions created with diagrams would lead to a higher level of understanding than viewing a description based solely on text. This hypothesis was confirmed. The second hypothesis suggested that viewing a domain description created using an object oriented grammar would lead to a higher level of "understanding" than viewing a description created using the "Structured Analysis" approach. The results confirmed the hypothesis that the group of participants using the Object-Oriented grammar scored higher in "understanding" than participants using the Structured Analysis grammar. A follow-up protocol analysis was undertaken to illuminate why the participants using object methods scored. The analysis of these protocols indicated two things. First, participants using Structured Analysis made little use of the Entity Relationship Diagram (ERD). Second, participants seemed to favor the "object" concept when answering questions. These findings provide some empirical evidence that objects may be more "natural" cognitive constructs than those used in Structured Analysis. The second study revisited a study Bodart and Weber's study regarding alternative grammars for the Entity Relationship Diagram. A grammar using mandatory attributes and relationships with sub types, the other using optional attributes and relationships, were compared. The grammars shared a common primary grammar, therefore, the second study was labeled an "Intragrammar" comparison. The new instrument was again used in this study. The ontological constructs proposed in the Bunge-Wand-Weber (BWW) model were used to suggest the theoretical advantage of the grammar using mandatory attributes and relationships with subtypes. The results supported the theoretical advantage associated with mandatory attributes and relationships with subtypes. This intragammar study provided further evidence of the utility of the empirical instrument proposed in this thesis. This study has implications for future empirical research in system analysis. The empirical instrument described in this thesis extends previous empirical research instruments with the introduction of the problem solving and the Cloze task. In two studies, the new instrument has displayed the sensitivity to differentiate between treatment groups. The results from the two empirical studies suggest that object-oriented analysis may hold advantages over traditional structured analysis, and that mandatory attributes and relationships may be preferred to optional attributes and relationships in the entity relationship grammar. / Business, Sauder School of / Management Information Systems, Division of / Graduate
3

System Design for DSP Applications with the MASIC Methodology

Deb, Abhijit Kumar January 2004 (has links)
The difficulties of system design are persistentlyincreasing due to the integration of more functionality on asystem, time-to-market pressure, productivity gap, andperformance requirements. To address the system designproblems, design methodologies build system models at higherabstraction level. However, the design task to map an abstractfunctional model on a system architecture is nontrivial becausethe architecture contains a wide variety of system componentsand interconnection topology, and a given functionality can berealized in various ways depending on cost-performancetradeoffs. Therefore, a system design methodology must provideadequate design steps to map the abstract functionality on adetailed architecture. MASIC—Maths to ASIC—is a system design methodologytargeting DSP applications. In MASIC, we begin with afunctional model of the system. Next, the architecturaldecisions are captured to map the functionality on the systemarchitecture. We present a systematic approach to classify thearchitectural decisions in two categories: system leveldecisions (SLDs) and implementation level decisions (ILDs). Asa result of this categorization, we only need to consider asubset of the decisions at once. To capture these decisions inan abstract way, we present three transaction level models(TLMs) in the context of DSP systems. These TLMs capture thedesign decisions using abstract transactions where timing ismodeled only to describe the major synchronization events. As aresult the functionality can be mapped to the systemarchitecture without meticulous details. Also, the artifacts ofthe design decisions in terms of delay can be simulatedquickly. Thus the MASIC approach saves both modeling andsimulation time. It also facilitates the reuse of predesignedhardware and software components. To capture and inject the architectural decisionsefficiently, we present the grammar based language of MASIC.This language effectively helps us to implement the stepspertaining to the methodology. A Petri net based simulationtechnique is developed, which avoids the need to compile theMASIC description to VHDL for the sake of simulation. We alsopresent a divide and conquer based approach to verify the MASICmodel of a system. Keywords:System design methodology, Signal processingsystems, Design decision, Communication, Computation, Modeldevelopment, Transaction level model, System design language,Grammar, MASIC.
4

System Design for DSP Applications with the MASIC Methodology

Deb, Abhijit Kumar January 2004 (has links)
<p>The difficulties of system design are persistentlyincreasing due to the integration of more functionality on asystem, time-to-market pressure, productivity gap, andperformance requirements. To address the system designproblems, design methodologies build system models at higherabstraction level. However, the design task to map an abstractfunctional model on a system architecture is nontrivial becausethe architecture contains a wide variety of system componentsand interconnection topology, and a given functionality can berealized in various ways depending on cost-performancetradeoffs. Therefore, a system design methodology must provideadequate design steps to map the abstract functionality on adetailed architecture.</p><p>MASIC—Maths to ASIC—is a system design methodologytargeting DSP applications. In MASIC, we begin with afunctional model of the system. Next, the architecturaldecisions are captured to map the functionality on the systemarchitecture. We present a systematic approach to classify thearchitectural decisions in two categories: system leveldecisions (SLDs) and implementation level decisions (ILDs). Asa result of this categorization, we only need to consider asubset of the decisions at once. To capture these decisions inan abstract way, we present three transaction level models(TLMs) in the context of DSP systems. These TLMs capture thedesign decisions using abstract transactions where timing ismodeled only to describe the major synchronization events. As aresult the functionality can be mapped to the systemarchitecture without meticulous details. Also, the artifacts ofthe design decisions in terms of delay can be simulatedquickly. Thus the MASIC approach saves both modeling andsimulation time. It also facilitates the reuse of predesignedhardware and software components.</p><p>To capture and inject the architectural decisionsefficiently, we present the grammar based language of MASIC.This language effectively helps us to implement the stepspertaining to the methodology. A Petri net based simulationtechnique is developed, which avoids the need to compile theMASIC description to VHDL for the sake of simulation. We alsopresent a divide and conquer based approach to verify the MASICmodel of a system.</p><p><b>Keywords:</b>System design methodology, Signal processingsystems, Design decision, Communication, Computation, Modeldevelopment, Transaction level model, System design language,Grammar, MASIC.</p>
5

An integrated systems-design methodology and revised model of sustainable development for the built environment in the Information Age

Macagnano, Marco January 2018 (has links)
This thesis was developed to investigate the current models of sustainable development and architectural working and design practice and process to respond to the challenges of the current era defined as the Information Age. This thesis proposes a new model of sustainable development aligned to architecture and the Information Age, and a new integrated systems-design methodology to support it. Buildings were defined by le Corbusier in 1927 as ‘machines for living in’1 on the premise that these buildings facilitated our day-to-day user experience. The role of architecture as a facilitator for a sustainable existence is therefore subject to continued investigation. While there has been an increasing interest in environmental issues and ‘green building’, built environments have consequently failed to effectively holistically integrate core sustainable development principles in architecture. When compared to the definition of sustainable development in the UN Brundlandt Report of 1987, further research into an architectural design methodology is required to enable and plan for the long-term success of our built environments for current and, importantly, future generations. The practices and production of architecture risk being limited to reactively monitoring the design and construction processes for fixed moments in time, usually after the problem has presented itself. This is representative of localised, yet much publicised trends involving quantifiable rating systems for building performance. This does not contribute to long-term sustainability of the architectural product, nor the core principle of sustainable development to adequately meet the needs of current and future generations. The gravitation towards these easily-followed, yet limited-in-scope checklist processes is symptomatic of concepts of sustainable development remaining too broad and fragmented to facilitate focused, industry-appropriate implementation and design. The digital and information-based revolution has arrived, and humankind has now progressed to the point where constant and pervasive access to information and communication in a world of connected systems has changed the way we live and work. This is occurring at an exponential rate within what have been termed ‘knowledge-based societies’. Furthermore, the influence of the Information Age continues to manifest itself in the built environment through advancement of concepts and initiatives such as Smart Cities, intelligent buildings, and the Internet of Things. However, architectural approach and its emphasis on the building as a finite product comes at the expense of a holistic and integrated systems approach, and therefore requires investigation towards a revised design methodology. This thesis will begin by investigating the concept of sustainable development from its original inception to existing interpretations, and will interrogate its continued significance as a decades-old concept to the Information Age. This will be undertaken on the basis that sustainable development primarily aligns itself to the needs of humankind (current and future generations) and as such remains timeless as a core concept. However, the criteria that define sustainable development require investigation based on: a) their suitability towards human need in the context of knowledge-based societies and the Information Age, as well as b) their appropriateness for focused implementation in the scope of the built environment. In this aim, newly proposed criteria will be assimilated into a revised model for sustainable development, from which a methodology for design is developed. This will address the nature of the architectural process towards the creation of sustainable building solutions as a function of a systems approach, rather than a product approach. An integrated systems-design methodology is proposed, promoting the evolution of sustainable development theory in architecture for greater applicability to the Information Age. This systems-design methodology proactively identifies criteria for solving a given problem and the development of alternative solutions, while the proposed revised model for sustainable development is integrated to achieve a holistic building solution based on a systems process. This is inclusive of product (systems solution) delivery into the operation phase. The designer and project information model therefore transition into ‘information custodian’ and repository for knowledge gathering and exchange respectively, to the benefit of current and future stakeholders. This is addressed through various stages in design development and implementation, which apply contextually-based requirements of proposed sustainable development criteria, while catering for aspects of future flexibility, user experience, and knowledge-based development. This methodology expects the design practitioner to apply multi-dimensional evaluation and assessment tools at their discretion, and accommodate changing project dynamics over its life cycle. This implementation will benefit from future research and the introduction of new technologies to aid the process. This may furthermore be affected by new regulatory policy and guidelines affecting architects and the built environment. / Thesis (PhD)--University of Pretoria, 2018. / Architecture / PhD / Unrestricted

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