840 research outputs found
CWA 17819:2021: Guidelines for the assessment of resilience of transport infrastructure to potentially disruptive events
No full textIndicator Based Framework To Quantify Hospital Resilience
No full textThis paper addresses the crucial issue of quantifying the resilience of hospitals. Hospitals are critical infrastructures within health systems which must be able to provide service when disruptive events occur, thus they need to be resilient. The aim of this paper is to present a novel indicator-based framework for quantifying the resilience of hospitals, where the indicator values are explicitly connected to the provided service. Qualitative
research methods were used to develop the framework, namely literature review and expert opinion. The framework is built upon the following steps: conceptualizing the hospital system, setting service measures, developing resilience indicators, estimating resilience against a specific disruptive event. The hospital system has been conceptualized into four key parts: staff, stock and supplies, space, system, emphasizing their interconnectedness. Twenty resilience indicators describe the essential features of a resilient hospital, regardless of the hazard type, while a set of service measures are used to quantify resilience. Hospital administrators and supervisory organizations can use the results of this paper to rapidly assess hospital resilience, or they can customize the proposed framework by changing service measures and adapting the indicators according to their needs. Finally, they can use the framework to clearly point out the weaknesses to ensure that improvement actions will have the largest possible impact in terms of resilience. Future applications are needed to test the validity of the framework and they may require adjustments to align with the context and the disruptive event of interest
Evaluating Initial Building Designs Considering Possible Future Changes and Decision Flexibility: The Example of The New PET Centre of the University Hospital of Zurich
No full textISSN:1911-110XISSN:1911-1118ISSN:1911-111
Quantitative evaluation of highway designs considering uncertainties in future mobility patterns and flexibility using real options
No full textDefining road service to facilitate road infrastructure asset management
No full textISSN:2053-0242ISSN:2053-0250ISSN:2053-025
A new process for the evaluation of the net-benefit of flexible ground-floor ceiling in the face of use transition uncertainty
No full textIn metropolitan areas, real estate investments, such as buildings, can be highly profitable. The profitability, however, can be uncertain, as adaptations might be required in the long-term to enable the modification of the building to adapt it to new uses. In building adaptation for use transitions, an important aspect is the modification of the ceiling height of the ground floor to meet the floor height requirements of different uses. Designs that include flexible ceilings instead of rigid ceilings have relatively low future adaptation costs, but are relatively expensive. Such designs are, therefore, only beneficial when the use transition costs over the life of the building are higher than the cost difference between the flexible and the rigid design. Because of the difficulties in predicting the number and types of adaptations that will occur over the life of a building, and the fact that flexible designs are more expensive, investors, to their own detriment, often build rigidly for current needs only. In the work presented in this article, a new process was developed and tested that uses Monte Carlo simulations to estimate costs and benefits of alternative ceiling designs, considering uncertainty on use transitions. The process is shown by using it to estimate the net-benefit over 70 years for an investor related to a fictive building in London with flexible ceilings and the same building with rigid ceilings. It was considered that multiple use transitions among five use categories (residential, retail, industrial, office, and other) were possible. It is shown that the process can be used to gain more insight into how buildings should be designed to maximize investor net-benefit, taking into consideration uncertain variables, such as use-change rate, construction costs and durations, discount factors and rents. A discussion of possible improvements to the process is given
Estimating and communicating the risk of neglecting maintenance
No full textISSN:2053-0242ISSN:2053-0250ISSN:2053-025
Considering automated vehicle deployment uncertainty in the design of optimal parking garages using real options
No full textParking garages are often currently designed assuming that parking demand will be stable over their lifetime. The looming mobility shift towards automated vehicles (AVs), however, makes parking demand highly uncertain, with some scenarios leading to its complete disappearance at some time in the near future. The design of optimal parking garages needs to take this uncertainty into consideration and may lead to parking garages that can easily be transformed for other uses when beneficial.In situations of large future demand uncertainty, infrastructure owners are increasingly using the real options method to help evaluate the potential benefits of paying more for construction of flexibly designed infrastructure. The real options method, helps owners, to avoid under-, or overinvesting in infrastructure, through the minimisation of their risks. In this work, a methodology, which uses the real options method, is proposed to determine the optimal design of a parking garage located within a residential building.The methodology is used, together with estimates of the uncertainty in the future parking demand due to deployment of AVs, Monte Carlo simulations of the possible futures, stakeholder costs for operation and refurbishment costs for each of the different design alternatives and intervention strategies, to estimate the net benefits over the life-time of the parking garage. The methodology is used to evaluate designs and intervention strategies for the 14000 m2 463-lot parking garage in a residential building in western Switzerland. The designs are a traditional design and a flexible design. The construction of a building according to the two design approaches would bear costs of 10 and 11 million CHF, respectively. The intervention strategies for the traditional building are a single stage intervention strategy and a no intervention strategy. The intervention strategies for the flexible building are a single-stage intervention strategy and a multi-stage intervention strategy. The traditionally designed building costs 2 million CHF to demolish and 29 million CHF to reconstruct as a residential building. The flexibly designed building costs 21 million to adapt for residential use.It is shown that the flexible design and a multi-stage intervention strategy (i.e. transforming the parking garage floor by floor on an as needed basis), provides the highest net benefits (2.2 million CHF). The flexible design and a single-stage intervention strategy provides the second highest net benefits (1.3 million CHF). A traditional design with a single-stage intervention strategy provides 0.5 million CHF in net benefit, and the traditional design with a no intervention strategy results in a net loss of 3.0 million CHF. A sensitivity analysis shows the robustness of the options.Since the use of the proposed methodology helps owners identify all the possible designs and intervention strategies as well as increases their ability to accurately estimate the net-benefit of their decisions, it is concluded that it is advantageous for owners to use the proposed methodology in determining the optimal design of parking garages. Its use will help ensure that they are optimally positioned to deal with the uncertain future
Initial Investigations into the Use of Three Heuristic Algorithms to Determine Optimal Intervention Programs for Multiple Railway Objects
No full textDetermination of Risk-Reducing Intervention Programs for Railway Lines and the Significance of Simplifications
No full textBecause failures on railway lines have nonzero probabilities of occurrence and can result in significant costs if they occur, railway infrastructure managers are interested in determining intervention programs that best reduce this risk, taking into consideration their budget constraints. In this paper, a base model is proposed to determine optimal risk-reducing intervention programs for railway lines based on the states of its objects and budget availability. The base model is an integer nonlinear model with an objective function that maximizes net benefit without exceeding budget constraints. The net benefit is the difference between the amount of risk reduction and the costs of executing interventions in terms of both direct costs (i.e.,materials and labor forces) and indirect costs (i.e.,the travel time costs). Three variations of the base model, i.e.,the object model, the block model, and the line model, are used to investigate the trade-offs between increasingly simplified models and decreasing ability to determine the optimal intervention program due to decreasing ability to accurately estimate costs and benefits. In the object model, objects are considered in isolation, i.e.,while each object fails and is restored all other objects in the line are fully functional. In the block model, blocks are observed in isolation, i.e.,while each block fails and is restored all objects in the line are fully functional, whereas the multiple objects within a block may fail and be restored simultaneously. In the line model, all objects in the line may fail and be restored simultaneously. Fault tree analysis is used in the block and line models to estimate the costs of the combined failures of multiple objects. The three models are demonstrated by using them to determine the optimal intervention program for a fictive railway line between two stations that consisted of eight track sections, a bridge, two switches, and two signals. The intervention programs determined using the three models in terms of the interventions included and the net benefit obtained are compared. It is shown that all three variations produce useful results but that there are significant differences in the estimation of the net benefits using the three different models, and that these differences lead to different interventions being included in the determined intervention programs, and consequently in the net benefit that will be achieved through their implementation. It was also shown that each improvement in the estimation of accuracy comes with an increase in modeling complexity. (c) 2017 American Society of Civil Engineers
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