Modelling Emergency Scenarios using Algebraic High Level Net Transformation Systems with Net Patterns

Emergency operations are a good case study for dynamic systems. Their size and high dynamicity make modelling them a challenging task. Algebraic high level net transformation systems are a well suited technique for modelling such dynamic systems. They consist of an algebraic high level net and a set of graph transformation rules. The net reflects the initial state of the operation and the transformation rules can be used to adapt this state to reflect the dynamicity of the operation. The applicability of graph transformation rules depends on the existence of a match morphism. While designing the algebraic high level net transformation system the designer has to ensure the existence of the right match morphisms for all reachable runtime states. This can be a tedious and error prone task for the designer. This paper uses a case study for modelling emergency operations with algebraic high level net transformation systems to show how the notion of net patterns can help the designer to cope with rule applicability

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

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

Discrete Event Simulations

Considered by many authors as a technique for modelling stochastic, dynamic and discretely evolving systems, this technique has gained widespread acceptance among the practitioners who want to represent and improve complex systems. Since DES is a technique applied in incredibly different areas, this book reflects many different points of view about DES, thus, all authors describe how it is understood and applied within their context of work, providing an extensive understanding of what DES is. It can be said that the name of the book itself reflects the plurality that these points of view represent. The book embraces a number of topics covering theory, methods and applications to a wide range of sectors and problem areas that have been categorised into five groups. As well as the previously explained variety of points of view concerning DES, there is one additional thing to remark about this book: its richness when talking about actual data or actual data based analysis. When most academic areas are lacking application cases, roughly the half part of the chapters included in this book deal with actual problems or at least are based on actual data. Thus, the editor firmly believes that this book will be interesting for both beginners and practitioners in the area of DES

Step-wise development of resilient ambient campus scenarios

This paper puts forward a new approach to developing resilient ambient applications. In its core is a novel rigorous development method supported by a formal theory that enables us to produce a well-structured step-wise design and to ensure disciplined integration of error recovery measures into the resulting implementation. The development method, called AgentB, uses the idea of modelling database to support a coherent development of and reasoning about several model views, including the variable, event, role, agent and protocol views. This helps system developers in separating various modelling concerns and makes it easier for future tool developers to design a toolset supporting this development. Fault tolerance is systematically introduced during the development of various model views. The approach is demonstrated through the development of several application scenarios within an ambient campus case study conducted at Newcastle University (UK) as part of the FP6 RODIN project. © 2009 Springer Berlin Heidelberg

Decision support strategies for the efficient implementation of circular economy principles in process systems

Economic growth at any expense is no longer an option. Awareness of the growing human footprint is crucial to face the problems that the impoverishment of ecosystems is causing and will cause in the future. One of the key challenges to address it is moving toward approaches to manage resources in a more sustainable way. In this light, circular economy stands as a promising strategy to improve the lifetime of resources by closing material and energy loops. The Process Systems Engineering (PSE) community has been developing methods and tools for increasing efficiency in process systems since the late 1980s. These methods and tools allow the development of more sustainable products, processes, and supply chains. However, applying these tools to circular economy requires special considerations when evaluating the introduction of waste-to-resource technologies. This Thesis aims at providing a set of models and tools to support in the decision-making process of closing material cycles in process systems through the implementation of waste-to-resource technologies from the circular economy perspective. The first part provides an overview of approaches to sustainability, presents the optimization challenges that circular economy and industrial symbiosis pose to PSE, and introduces the methodological and industrial scope of the Thesis. Part two aims at assessing the environmental and economic reward that may be attained through the application of circular economy principles in the chemical industry. With this purpose, a systematic procedure based on Life Cycle Assessment (LCA), economic performance and Technology Readiness Level (TRL) is proposed to characterize technologies and facilitate the comparison of traditional and novel technologies. The third part describes groundwork tasks for optimization models. A methodology is presented for the systematic generation of a list of potential waste-to-resource technologies based on an ontological framework to structure the information. In addition, this part also presents a targeting approach developed to include waste transformation and resource outsourcing, so a new dimension of potential destinations for waste are explored for the extension of material recovery. Finally, part four includes the development of decision-making models at the strategic and tactical hierarchical levels. At the network level, a framework is presented for the screening of waste-to-resource technologies in the design of process networks. The most promising processing network for waste recovery is identified by selecting the most favorable waste transformation processes among a list of potential alternatives. After the network selection, an optimization model is built for the detailed synthesis of individual processes selected in the resulting network. The developed methodologies have been validated and illustrated through their application to a case study under different viewpoints in the process industry, in particular to the chemical recycling of plastic waste. Despite the low Technology Readiness Level of some chemical recycling technologies, the results of this Thesis reveal pyrolysis as a promising technology to close the loop in the polymer sector. Overall, all these positive outcomes prove the advantages of developing tools to systematically integrate waste-to-resource processes into the life cycle of materials. The adaptation to this change of perspective of the well-established methods developed by the PSE community offers a wide range of opportunities to foster circular economy and industrial symbiosis. This Thesis aims to be a step forward towards a future with more economically efficient and environmentally friendly life cycles of materials.El crecimiento económico a cualquier precio ha dejado de ser una opción viable. Tener conciencia sobre nuestra creciente huella ambiental es clave para afrontar los problemas que el empobrecimiento de los ecosistemas está causando y causará en el futuro. Uno de los desafíos clave para abordarlo es avanzar hacia técnicas que permitan una gestión de recursos más sostenible. En esta línea, la economía circular es una estrategia con gran potencial para mejorar la vida útil de los recursos mediante el cierre de ciclos de materiales y energía. Desde finales de los años ochenta, la investigación en Ingeniería de Procesos y Sistemas (PSE) ha permitido generar métodos y herramientas para el desarrollo sostenible de productos, procesos y cadenas de suministro. Sin embargo, su aplicación en economía circular requiere consideraciones especiales al evaluar la introducción de nuevas tecnologías para el reciclaje de materiales. Esta Tesis tiene como objetivo proporcionar un conjunto de modelos y herramientas para apoyar el proceso de toma de decisiones sobre el aprovechamiento de materiales a través de la lente de la economía circular mediante la implementación de tecnologías de conversión de residuos en recursos. La primera parte presenta una visión general de los enfoques de sostenibilidad, lista los desafíos que la economía circular y la simbiosis industrial plantean en PSE, e introduce el alcance metodológico e industrial de la Tesis. La segunda parte tiene como objetivo evaluar los beneficios ambientales y económicos que se pueden obtener mediante la aplicación de los principios de la economía circular en la industria química. Con este propósito, se desarrolla un método sistemático basado en el análisis del ciclo de vida, el rendimiento económico y el nivel de madurez tecnológica para caracterizar las tecnologías de recuperación y facilitar la comparación entre técnicas tradicionales y en desarrollo. La tercera parte describe las tareas previas al desarrollo de los modelos de optimización. Se presenta una metodología para la generación sistemática de una lista de posibles tecnologías de conversión de residuos en recursos utilizando en un marco ontológico para estructurar la información. Además, se expone un método para acotar la transformación de residuos y la externalización de recursos, que permite explorar una nueva dimensión de destinos potenciales para los residuos, extendiendo así el grado de recuperación de materiales. Por último, la cuarta parte incluye el desarrollo de modelos de toma de decisiones a nivel estratégico y táctico. A nivel estratégico, se presenta un marco para la detección de tecnologías de reciclaje de residuos en el diseño de redes de procesos. Tras sintetizar la red, a nivel táctico se construye un modelo de optimización para el diseño detallado de los procesos individuales seleccionados en el mismo. Las metodologías desarrolladas han sido ilustradas y validadas a través de su aplicación en un caso de estudio con diferentes perspectivas sobre el reciclaje químico de residuos plásticos. A pesar del bajo nivel de madurez tecnológica de los procesos de reciclaje químico, los resultados de esta Tesis permiten identificar el gran potencial económico y ambiental de la pirolisis de residuos plásticos para cerrar su ciclo de materiales. En conjunto, los resultados demuestran las ventajas de desarrollar herramientas para integrar sistemáticamente los procesos de reciclaje de residuos en el ciclo de vida de los materiales. La adaptación a las necesidades de este cambio de perspectiva de métodos bien establecidos en la comunidad PSE ofrece grandes oportunidades para fomentar la economía circular y la simbiosis industrial. Esta tesis pretende ser un paso adelante hacia un futuro con ciclos de vida de materiales económica y ambientalmente más eficientes