A Resilience Index for Process Safety Analysis

PresentationQualitative risk analysis is focused on applying methods to prevent accidents in diverse process plants. The numerical number resulting in the QRA tells nothing about the ability for systems’ recovery if an upset related to safety occurs in the process. Hence a resilience study is required to produce this additional information related to process safety. The resilience index is defined as the proportion of success in recovering the system compared to a number of safety-related upsets. The failure in recovering depends on type and quality of safety barriers, i.e. technology, but also on organizational principles. In this work, Monte Carlo simulation is carried out to estimate the resilience resulting in quantitative resilience estimations. These results provide means to compare processes from a more general safety point of view

Integrated design and control of chemical processes : part I : revision and clasification

[EN] This work presents a comprehensive classification of the different methods and procedures for integrated synthesis, design and control of chemical processes, based on a wide revision of recent literature. This classification fundamentally differentiates between “projecting methods”, where controllability is monitored during the process design to predict the trade-offs between design and control, and the “integrated-optimization methods” which solve the process design and the control-systems design at once within an optimization framework. The latter are revised categorizing them according to the methods to evaluate controllability and other related properties, the scope of the design problem, the treatment of uncertainties and perturbations, and finally, the type the optimization problem formulation and the methods for its resolution.[ES] Este trabajo presenta una clasificación integral de los diferentes métodos y procedimientos para la síntesis integrada, diseño y control de procesos químicos. Esta clasificación distingue fundamentalmente entre los "métodos de proyección", donde se controla la controlabilidad durante el diseño del proceso para predecir los compromisos entre diseño y control, y los "métodos de optimización integrada" que resuelven el diseño del proceso y el diseño de los sistemas de control a la vez dentro de un marco de optimización. Estos últimos se revisan clasificándolos según los métodos para evaluar la controlabilidad y otras propiedades relacionadas, el alcance del problema de diseño, el tratamiento de las incertidumbres y las perturbaciones y, finalmente, el tipo de la formulación del problema de optimización y los métodos para su resolución

A framework for assessing robustness of water networks and computational evaluation of resilience.

Arid regions tend to take careful measures to ensure water supplies are secured to consumers, to help provide the basis for further development. Water distribution network is the most expensive part of the water supply infrastructure and it must maintain performance during unexpected incidents. Many aspects of performance have previously been discussed separately, including reliability, vulnerability, flexibility and resilience. This study aimed to develop a framework to bring together these aspects as found in the literature and industry practice, and bridge the gap between them. Semi-structured interviews with water industry experts were used to examine the presence and understanding of robustness factors. Thematic analysis was applied to investigate these and inform a conceptual framework including the component and topological levels. Robustness was described by incorporating network reliability and resiliency. The research focused on resiliency as a network-level concept derived from flexibility and vulnerability. To utilise this new framework, the study explored graph theory to formulate metrics for flexibility and vulnerability that combine network topology and hydraulics. The flexibility metric combines hydraulic edge betweenness centrality, representing hydraulic connectivity, and hydraulic edge load, measuring utilised capacity. Vulnerability captures the impact of failures on the ability of the network to supply consumers, and their sensitivity to disruptions, by utilising node characteristics, such as demand, population and alternative supplies. These measures together cover both edge (pipe) centric and node (demand) centric perspectives. The resiliency assessment was applied to several literature benchmark networks prior to using a real case network. The results show the benefits of combining hydraulics with topology in robustness analysis. The assessment helps to identify components or sections of importance for future expansion plans or maintenance purposes. The study provides a novel viewpoint overarching the gap between literature and practice, incorporating different critical factors for robust performance

Using isotopic niche dynamics to predict resiliency to climate change in an Arctic seabird

Resource limitation drives fitness-related decisions and constrains the ability of organisms to invest in energetically demanding life history stages. Environmental factors (e.g., temperature) play an important role in affecting resource availability and quality which can downstream effect the ability of individuals to invest in energetically demanding life history stages, including reproduction. Human-induced climate change is generating increasingly variable environmental conditions, impacting the abundance and distribution of prey items and therefore the ability of individuals to successfully reproduce, and these effects are especially pronounced in the Arctic. However, it is currently unknown whether Arctic organisms possess the ability to adjust foraging decisions and prey selection to overcome newly emerging environmental constraints. Quantifying stable isotopes in the tissues of consumers provides a minimally invasive method of inferring foraging niche; however, has yet to be validated as a method of predicting population-level resiliency to climate change. Seabirds are a useful system to test these linkages in because they are wide-ranging, predominantly oceanic-based group, reliant on marine-based resources and they are often widely distributed across polar regions. Using common eiders (Somateria mollissima), an Arctic diving seabird, as a model organism, this thesis examines the linkages between environmental variation, isotopic variation in foraging niche, and breeding parameters, as a means of predicting the resiliency of Arctic seabirds to the effects of climate change. Using a long term data set from a focal breeding colony, I found significant inter-annual and inter-breeding stage variation in isotopes and isotopic niche. Although environmental cues only weakly predicted variation in isotopic niche, variation in isotopic niche was a key predictor of breeding probability. Given that variation in isotopic niche has fitness-related impacts, I then took a species-wide approach to assess inter-colony variation in isotopic niche by sampling 8 breeding colonies across the distribution of eiders. While common eiders are a generalist species overall, individual colonies had significantly different foraging strategies and levels of generalization. Taken together, these results suggest that common eiders are likely to be resilient in the face of climate change, but some colonies may be more at risk from the ongoing effects of climate change. This thesis provides the first steps towards developing a minimally invasive method for foraging flexibility as a means of assessing the resiliency of Arctic seabirds to climate change

Designing Resilient Manufacturing Systems In the Presence of Change

Economic and technical changes force manufacturers to redesign and enhance their operational systems. The implications of such changes within a complex system such as manufacturing and the supply chain can be very challenging. In particular, where the number of system elements and their connections result in a high level of complexity, the potential effects of a change can be expensive concerning the delivery time and cost targets, as a change to one part or element of a design requires additional changes throughout the system. Companies need to understand the characteristics of their manufacturing systems that make them resilient to change. Considered from a system perspective, the structures of the system, and its elements and connections, contribute greatly to the characteristics and behavior of the system and hence potential resilience. A change prediction method can help to analyse the change properties and improve complex systems by focusing on the underlying structural elements and dependencies. This thesis proposes a novel system change method that can enable the review of the current manufacturing system and understand how to design a more robust or adaptable system that addresses resilience. This method is a combination of matrix-based approaches and methods to assess the interaction between elements of the product and its manufacturing process in order to understand the risk of changes propagating through the system. Risk assessment across layers of a system can give valuable insight into how an element change interacts within the system. The goal of this thesis is to contribute to gaining a fundamental understanding of manufacturing systems resilience by developing a method to evaluate capabilities of changes, performance robustness or adaptability, and achieving high resilience.Universal Oil Products (a Honeywell Company); Laing O’Rourk

The Gaian-Inspired Systems View of Life: A Systemic Approach to Global Crises A Case Study: How Scientific Worldviews Influence Global Food Systems

This Master\u27s Paper relies on secondary research in addition to theoretical and philosophical arguments to show that humanity\u27s metaphysical worldview significantly underlies its valuing systems, institutions, and behavior. The paper uses the examples of modern industrial food production and emerging organic and local alternatives to provide a comparative analysis between fundamental worldviews and how they influence the way human systems originate and function. It is argued that the change required to address substantial and interconnected global issues will require a re-evaluation and scrutiny of the metaphysical assumptions inherent in the politics and practice of agriculture, food processing, and the very act of eating itself. This paper ultimately connects the modern metaphysical worldview to the spread of neoliberal capitalism and offers evidence that the current globalizing capitalist economy cannot be sustained indefinitely. The space behind our individual thinking dictates what we value, prioritize, and the ways in which we behave and perceive each other and the world. Social change in the form of a metaphysical shift in worldview is required to bring about the mandatory evolution of global society including but not limited to the creation of a sustainable food production-consumption paradigm

Enhancing Set-Based Design To Engineer Resilience For Long-Lived Systems

At the heart of Set-Based Design is the concept that down-select decisions are deferred until sufficient information is available to make a decision, i.e., a set of possible solutions is maintained. Due to the extended service lives of many of our current and future systems, the horizon for accurately predicting the system’s requirement is shorter than the service life, so the needed information to down-select to a single optimized solution is unavailable at the time of fielding. Set-Based Design can, however, be extended to explicitly carry a set of possible solutions past the point of the initial fielding of the system by considering changeability, as enabled through designed-in reserve capacity to accommodate additional volume, weight, power, cooling, and computer performance. Proposed is an analytical framework that enhances Set-Based Design to engineer resilient systems with cost-effective post-production growth capability by means of reserve capacity and illustrate it through a case study