PhD Theses

Domains & Disciplines | PhD Theses | Diploma Theses

So far, five PhD students have succesfully acquired a doctorate from the ErgoU while five other are working on dissertation under the direction of Prof. Nicolas Marmaras. The topics under study are the following:

» On-going PhD research projects

The Interplay between Information System Development and Organisational Change.

ABSTRACT
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Ergonomic Design of Information Systems through a Pragmatic Approach.

ABSTRACT
The present thesis is concerned with the design of information systems which support human work. At the present time the situation can be deemed problematic: systems development is purely technology driven, and not driven by the needs of the worksystem. Meanwhile, Ergonomics is constrained in evaluating systems after they’re built, and this only in the shallow “interface usability” layer. The belief supported in this thesis is that this problematic situation is due to the fact that both technological and ergonomics approaches follow a positivist approach, which has shown its value in purely technological problems, but is insufficient in dealing with the complexity of a worksystem that involves humans and organizational schemes. This thesis promotes a new approach for the analysis and design of information systems that will support work, which is based in the tradition of Pragmatism, and gives primacy to the daily coping of people and their interactions with the artefacts that comprise the worksystem. In order to gain an in-depth understanding of such phenomena, we need new tools for the analysis and interpretation of worksystems, and also a new view to intervene through new designs. This thesis is an attempt to explore the possibilities of this approach. In the first chapter, the two basic approaches to information systems design are presented: the positivist-conservative and the pragmatist. In the second chapter we refer to systems theory as a base for the analysis of the ontology and dynamics of worksystems. We elaborate on two views in studying systems: the externalist and the internalist. The third chapter is about the analysis of worksystems which will lead to new designs that will support them. The externalist and internalist views lead to different paths; the first to a hierarchical approach which focuses on structure and leads to early modelling, while the second to a flat models and focuses on process. In the 4th chapter is about the central case study of the dissertation. We used a multimethodological approach to the analysis of the anaesthesiologists’ practice. We focused in the anaesthesia chart, where the anaesthesiologist records the evolution of the patients’s vital signs, as well as the drugs administered. The development in healthcare informatics lead to a need for its digitization. In order to study the system we proceeded in a series of field studies using a systemic approach. During the analysis of the system we discovered that we shouldn’t regard as part of the system only the anaesthesiologist, but the whole anaesthesia team, since the anaesthesiologist is not present during the whole duration of the operation, and is substituted at regular intervals with the resident and the nurse. These changes create gaps in the team’s knowledge of the patient’s status, which can be completed by the anaesthesia chart. Through the wider analysis of the system offered by the internalist approach, we discovered that the diagram is not only used as a tool, but also as evidence in trials of medical malpractice: the majority of anaesthesiologists completed after the end of the operation, and then only with “normalized” data. Both of these findings belong to the kind that can’t be captured by approaches following an externalist view, which proceed to early modeling and as a result are distanced from the real world. The fifth chapter is about the design and development of artefacts. At first, classic design methods are presented, which are based on two positivist views: 1) the result of the design is qualitively unaffected from the tools used and 2) analysis of the worksystem is able to predict the future state of the system and predetermine it through the designed artifact. These views are contested as design tools can qualitevely affect design and the future state of practice is impossible to be fully predicted because of the emergence of the task-artefact cycle. The task-artefact cycle is about the unavoidable inter-adaptation of artifact and worksystem, which transforms both. In order to overcome the limitations of earlier methods, flexible methods were developed which transcend the cycle, through iterative development cycles. As a tool to support the inter-adaptation of artifact-worksystem we use the notion of “shearing layers”, and propose a new design process which ensures that the final definition of the design is through real use.


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A Method for the Management of Risks in Complex Sociotechnical Systems using Agent-based Simulation.

ABSTRACT
As technology advances, complex systems become very difficult to manage. In this dissertation we attempt to bridge the theoretical knowledge from two diversified fields, namely Complexity Science and Cognitive Engineering. The output is a methodological framework that can assist the designer of building efficient interventions in complex socio-technical systems. The skeleton of the method lays in the so-called Complex Adaptive Systems theory. Based on the notion of complexity, the system is represented through a bottom-up multi-agent simulation model. Using the simulation as a tool for the production of new knowledge, as opposed to its wide use as a prosthesis for the amplification of human skills in everyday problems, we seek for the identification of patterns of suboptimal performance and their links to structures that favour their emergence. Optimisation of the whole is sought through the alleviation of these structures, by alterations on the dimensionality of the agents that colonise the system. In this sense, by controlling emergence, we can reach to constraint-based designs, which are in compliance to the mechanisms that govern the complex system's evolution, in time and space. This method has been applied in a metro railway system, for the design of the means that would assist the personnel in command of an emergency evacuation, upon a train fire in a tunnel. Three co-evolving wholes where identified, namely the Fire (Fi) , the Railway System (RS) (comprising the Technological System and the Personnel in Command of the Evacuation) and the Group of Passengers (GoP). The agent-based model built (see the figure above), was proven capable of uniting the micro-world of individual performance, with the macro-world of collective behaviour, as well as it was capable of addressing the indirect interactions between the personnel in command and the group of passengers, evacuating the train. The agent-based simulation was built on Java, using the RePast toolkit (see above for a screenshot of the simulation). The proposed design did not have the form of a plan; instead it consisted of a web of constraints, leaving this way to the personnel, the opportunity and the responsibility to finish up the design, ad hoc, as the incident evolves. Under that scheme, the plan becomes dynamic, being able to adapt to the stimuli provided to the personnel by the environment, promising so far better collective adaptive performance, on behalf of the whole.



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Towards a Phenomenological Approach to the Analysis of Cognitive Systems: Contribution to the design of complex information systems

ABSTRACT
The present Phd deals with the development of a theoretical - methodological framework for the analysis and re-design of cognitive systems, that is, of systems composed of people and artifacts that develop and exploit knowledge to achieve a specified objective. More specifically, the present work concentrates on cognitive systems that use or are about to use information technology as an aid for the organization and coordination of human activity. Thus, the proposed theoretical - methodological framework is especially relevant for the design and/or implementation of information systems such as decision support systems, collaboration and workflow systems, as well as knowledge man-agement) etc. Contrary to the traditional frameworks for the analysis of cognitive systems which draw their axioms form analytical philosophy and formal logic, the proposed framework draws its theoretical background and axioms form the philosophical school of phenomenology. The traditional frameworks tend to consider knowledge, as a structure independent from its carriers and the situations in which it is manifested, and thus as a storable resource. The phenomenological perspective considers knowledge as a process that is manifested and evolves only though the experience of specific autonomous agents in specific situations. At a technical level, the proposed framework proposes the modeling of cognitive processes using a typology borrowed form historical cultural psychology, that of the artifact mediated action. It is demonstrated how this typology is flexible enough to map the process of cognition in specific situations, and how it is expanded to map cognition from the individual to the collective level. The level of description is not that of infor-mation flow and transformation but of action performance (although a description in information terms may be used as complementary). Because it is based on actions and not information, the proposed theoretical methodological framework overcomes the usual consideration of human cognition as strictly information processing. This difference can be summarized as follows. Contrary to the information processing hypothesis, the proposed approach:

The research which gave rise to the framework is based on the experience gained in the design, implementation and usability evaluation of a number of information technology systems built to support complex non-routine individual activities as well as communities of practice which evolve in a turbulent environment.



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Modeling the ergonomic design of computerized office layout, and development of an information technology tool

ABSTRACT
The problem of designing computerized office layouts is complex; to solve this problem the designer should take into consideration an important number of factors and constraints describing the requirements of the office users and the building characteristics, and conceive solutions which satisfy a number of predetermined criteria. The difficulty of the designer's task is mainly due to the number and the interdependence between these criteria, factors and constraints. The aim of the present thesis was to develop a systematic process to design office layouts meeting the ergonomic principles concerning computerized offices, and an information technology tool supporting this process. More specifically throughout this study:

To ensure the usability of the information technology tool, we adopted the user-centered and problem-driven approach. The proposed office layout design process alleviates the design task at a cognitive level. In fact, the designer throughout the different design stages solves simpler problems than a complex one. Furthermore, the developed design suggestions ensure the consideration of all the ergonomic principles and requirements, gradually at the different design stages. Using the designed information technology tool, the designer's task is further facilitated through appropriate guidance and memory support provided by (i) the graphical representation of a number of constraints, (ii) the automation of the required calculations, (iii) the presentation of the corresponding design suggestions at the different design stages, (iv) the graphical calculation and representation of the proximity requirements between the different working groups, using the graphs theory. Therefore, adopting the proposed office layout design process and using the information technology tool, significantly contributes to the design of office spaces which meet the ergonomic principles and the functional requirements. Consequently, the employees' activity within the designed space becomes more efficient, safe and productive. Finally, the office furniture firms, using the information technology tool, obtain a competitive advantage, since they are able to offer not just ergonomically designed office furniture and equipment, but ergonomic layouts, as well.


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Applying Ecological Interface Design to Complex Socio-technical Systems: The Case of Electricity Distribution Systems

ABSTRACT
Electricity distribution management during critical operational conditions meets all the constraints that ecological design aims to support: large-scale, multi-component, distributed and highly interactive system, many points of interaction among a variety of agents, and a time- and safety- critical environment, where unfamiliar and unanticipated events may occur. This dissertation attempts to meet the theoretical and pragmatic challenges that emerge from the application of Ecological Interface Design (EID) to complex socio-technical systems, by the design of an Ecological Interface that is intended to support effectively electricity distribution operations during critical operational conditions. EID has already been applied in diverse domains? however, most of these design attempts and evaluations concerned microworlds. Scaling up from generic process simulations to larger systems demands appropriate adaptation of the EID framework, as well as integration of EID with field study methods, theories of cognition and collaboration for distributed environments, and effective information visualization concepts. Ethnographic analysis was performed first, in order to capture: the global physical and organizational characteristics of the system, the general properties of the information flow, the cognitive properties of the artefacts used, the social organization and culturally established practices, as well as to detect the interventions made by operators to overcome the limitations of the existing interface. A broadened Cognitive Work Analysis (CWA) was implemented next, in order to identify the constraints that the distribution operations' ecology imposes on action. CWA helped to integrate the previously collected field data into a coherent and useful model of the joint-cognitive system and to set the design requirements. The design requirements elicited by CWA were transformed to interface representations through a semantic mapping process, by which goal-relevant structures and relations of the work domain were mapped to display structures across the space, scale and time dimensions. In order to envision how the developed ecological interface representations will affect the cognitive activities of the operators, the cooperative processes, and the socio-organizational structure of the work system, a participatory design approach was adopted. Through iterative design of prototypes (from preliminary low-fidelity media prototypes to dynamic Macromedia Flash - based prototypes), open issues of interface design decisions were discussed and alternate design solutions were "worked out" with skilled domain practitioners (i.e., operators and engineers), in order to achieve a smooth integration of ecological design and organizational change. The Ecological Interface is now at its final stage of development. The complete ecological interface will be evaluated by expert operators, using a number of real scenarios, in order to test its effectiveness and efficiency against operationally critical conditions.


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