115,983 research outputs found

    Drawing the line: balancing the spatial requirements of customer and contractor in occupied refurbishment

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    In planning the refurbishment of railway stations the spatial needs of the contractor and ofthe ongoing business stakeholders have to be balanced. A particular concern is thedisruptive effect of construction works upon pedestrian movement.RaCMIT (Refurbishment and Customer Movement Integration Tool) is a research projectaimed at addressing this problem through combining the knowledge of the client projectmanager, the construction planner and the pedestrian modelling expert.The objective of the research is to develop a decision protocol (based on problemsencountered in two case studies) facilitating optimisation of overall project value to theclient?s business.Research observations as well as current literature suggest that:? for overall decision-making, opportunities may be lost (under current practice) forminimising joint project cost/revenue disruption and? for spatial decision-making, temporary station configuration during construction(and not just overall pedestrian capacity) is a significant variable for both businessand safety outcomes. In planning the refurbishment of railway stations the spatial needs of the contractor and ofthe ongoing business stakeholders have to be balanced. A particular concern is thedisruptive effect of construction works upon pedestrian movement.RaCMIT (Refurbishment and Customer Movement Integration Tool) is a research projectaimed at addressing this problem through combining the knowledge of the client projectmanager, the construction planner and the pedestrian modelling expert.The objective of the research is to develop a decision protocol (based on problemsencountered in two case studies) facilitating optimisation of overall project value to theclient?s business.Research observations as well as current literature suggest that:? for overall decision-making, opportunities may be lost (under current practice) forminimising joint project cost/revenue disruption and? for spatial decision-making, temporary station configuration during construction(and not just overall pedestrian capacity) is a significant variable for both businessand safety outcomes

    Balancing operating revenues and occupied refurbishment costs 1: problems of defining project success factors and selecting site planning methods

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    In planning the refurbishment of railway stations the spatial needs of the contractor and of the ongoing business stakeholders have to be balanced. A particular concern is the disruptive effect of construction works upon pedestrian movement. RaCMIT (Refurbishment and Customer Movement Integration Tool) was a research project aimed at addressing this problem. The objective of the research was to develop a decision protocol facilitating optimisation of overall project value to the client's business. This paper (the first of two) presents a framework for considering public disruption in occupied refurbishment using two case studies in large railway stations as examples. It briefly describes new tools which (combined with existing techniques) assist decision making in the management of disruption. It links strategic with sitebased decision making and suggests how public disruption may be treated as a variable to be jointly optimised along with traditional criteria such as time, cost and quality. Research observations as well as current literature suggest that for overall decision-making, opportunities may be lost (under current practice) for minimising joint project cost/revenue disruption, and, for spatio-temporal site decision-making, effective and efficient tools now exist to model both sides of the construction site boundary

    The integrated use of enterprise and system dynamics modelling techniques in support of business decisions

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    Enterprise modelling techniques support business process re-engineering by capturing existing processes and based on perceived outputs, support the design of future process models capable of meeting enterprise requirements. System dynamics modelling tools on the other hand are used extensively for policy analysis and modelling aspects of dynamics which impact on businesses. In this paper, the use of enterprise and system dynamics modelling techniques has been integrated to facilitate qualitative and quantitative reasoning about the structures and behaviours of processes and resource systems used by a Manufacturing Enterprise during the production of composite bearings. The case study testing reported has led to the specification of a new modelling methodology for analysing and managing dynamics and complexities in production systems. This methodology is based on a systematic transformation process, which synergises the use of a selection of public domain enterprise modelling, causal loop and continuous simulationmodelling techniques. The success of the modelling process defined relies on the creation of useful CIMOSA process models which are then converted to causal loops. The causal loop models are then structured and translated to equivalent dynamic simulation models using the proprietary continuous simulation modelling tool iThink

    A Framework for Evaluating Model-Driven Self-adaptive Software Systems

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    In the last few years, Model Driven Development (MDD), Component-based Software Development (CBSD), and context-oriented software have become interesting alternatives for the design and construction of self-adaptive software systems. In general, the ultimate goal of these technologies is to be able to reduce development costs and effort, while improving the modularity, flexibility, adaptability, and reliability of software systems. An analysis of these technologies shows them all to include the principle of the separation of concerns, and their further integration is a key factor to obtaining high-quality and self-adaptable software systems. Each technology identifies different concerns and deals with them separately in order to specify the design of the self-adaptive applications, and, at the same time, support software with adaptability and context-awareness. This research studies the development methodologies that employ the principles of model-driven development in building self-adaptive software systems. To this aim, this article proposes an evaluation framework for analysing and evaluating the features of model-driven approaches and their ability to support software with self-adaptability and dependability in highly dynamic contextual environment. Such evaluation framework can facilitate the software developers on selecting a development methodology that suits their software requirements and reduces the development effort of building self-adaptive software systems. This study highlights the major drawbacks of the propped model-driven approaches in the related works, and emphasise on considering the volatile aspects of self-adaptive software in the analysis, design and implementation phases of the development methodologies. In addition, we argue that the development methodologies should leave the selection of modelling languages and modelling tools to the software developers.Comment: model-driven architecture, COP, AOP, component composition, self-adaptive application, context oriented software developmen

    Exploiting Qualitative Information for Decision Support in Scenario Analysis

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    The development of scenario analysis (SA) to assist decision makers and stakeholders has been growing over the last few years through mainly exploiting qualitative information provided by experts. In this study, we present SA based on the use of qualitative data for strategy planning. We discuss the potential of SA as a decision-support tool, and provide a structured approach for the interpretation of SA data, and an empirical validation of expert evaluations that can help to measure the consistency of the analysis. An application to a specific case study is provided, with reference to the European organic farming business

    A Process Modelling Framework Based on Point Interval Temporal Logic with an Application to Modelling Patient Flows

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    This thesis considers an application of a temporal theory to describe and model the patient journey in the hospital accident and emergency (A&E) department. The aim is to introduce a generic but dynamic method applied to any setting, including healthcare. Constructing a consistent process model can be instrumental in streamlining healthcare issues. Current process modelling techniques used in healthcare such as flowcharts, unified modelling language activity diagram (UML AD), and business process modelling notation (BPMN) are intuitive and imprecise. They cannot fully capture the complexities of the types of activities and the full extent of temporal constraints to an extent where one could reason about the flows. Formal approaches such as Petri have also been reviewed to investigate their applicability to the healthcare domain to model processes. Additionally, to schedule patient flows, current modelling standards do not offer any formal mechanism, so healthcare relies on critical path method (CPM) and program evaluation review technique (PERT), that also have limitations, i.e. finish-start barrier. It is imperative to specify the temporal constraints between the start and/or end of a process, e.g., the beginning of a process A precedes the start (or end) of a process B. However, these approaches failed to provide us with a mechanism for handling these temporal situations. If provided, a formal representation can assist in effective knowledge representation and quality enhancement concerning a process. Also, it would help in uncovering complexities of a system and assist in modelling it in a consistent way which is not possible with the existing modelling techniques. The above issues are addressed in this thesis by proposing a framework that would provide a knowledge base to model patient flows for accurate representation based on point interval temporal logic (PITL) that treats point and interval as primitives. These objects would constitute the knowledge base for the formal description of a system. With the aid of the inference mechanism of the temporal theory presented here, exhaustive temporal constraints derived from the proposed axiomatic system’ components serves as a knowledge base. The proposed methodological framework would adopt a model-theoretic approach in which a theory is developed and considered as a model while the corresponding instance is considered as its application. Using this approach would assist in identifying core components of the system and their precise operation representing a real-life domain deemed suitable to the process modelling issues specified in this thesis. Thus, I have evaluated the modelling standards for their most-used terminologies and constructs to identify their key components. It will also assist in the generalisation of the critical terms (of process modelling standards) based on their ontology. A set of generalised terms proposed would serve as an enumeration of the theory and subsume the core modelling elements of the process modelling standards. The catalogue presents a knowledge base for the business and healthcare domains, and its components are formally defined (semantics). Furthermore, a resolution theorem-proof is used to show the structural features of the theory (model) to establish it is sound and complete. After establishing that the theory is sound and complete, the next step is to provide the instantiation of the theory. This is achieved by mapping the core components of the theory to their corresponding instances. Additionally, a formal graphical tool termed as point graph (PG) is used to visualise the cases of the proposed axiomatic system. PG facilitates in modelling, and scheduling patient flows and enables analysing existing models for possible inaccuracies and inconsistencies supported by a reasoning mechanism based on PITL. Following that, a transformation is developed to map the core modelling components of the standards into the extended PG (PG*) based on the semantics presented by the axiomatic system. A real-life case (from the King’s College hospital accident and emergency (A&E) department’s trauma patient pathway) is considered to validate the framework. It is divided into three patient flows to depict the journey of a patient with significant trauma, arriving at A&E, undergoing a procedure and subsequently discharged. Their staff relied upon the UML-AD and BPMN to model the patient flows. An evaluation of their representation is presented to show the shortfalls of the modelling standards to model patient flows. The last step is to model these patient flows using the developed approach, which is supported by enhanced reasoning and scheduling
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