Multi-criteria decision-making considering risk and uncertainty in physical asset management

In this work we present a method for risk-informed decision-making in the physical asset management context whereby risk evaluation and cost-benefit analysis are considered in a common framework. The methodology uses quantitative risk measures to prioritize projects based on a combination of risk tolerance criteria, cost-benefit analysis and uncertainty reduction metrics. There is a need in the risk and asset management literature for a unified framework through which quantitative risk can be evaluated against tolerability criteria and trade-off decisions can be made between risk treatment options. The methodology uses quantitative risk measures for loss of life, loss of production and loss of property. A risk matrix is used to classify risk as intolerable, As Low As Reasonably Practicable (ALARP) or broadly tolerable. Risks in the intolerable and ALARP region require risk treatment, and risk treatment options are generated. Risk reduction benefit of the treatment options is quantified, and cost-benefit analysis is performed using discounted cashflow analysis. The Analytic Hierarchy Process is used to derive weights for prioritization criteria based on decision-maker preferences. The weights, along with prioritization criteria for risk reduction, tolerance criteria and project cost, are used to prioritize projects using the Technique for Order Preference by Similarity to Ideal Solution. The usefulness of the methodology for improved decision-making is illustrated using a numerical example.     

Risk assessment and risk reduction of an acrylonitrile production plant

Reducing accident occurrence in petrochemical plants is crucial, thus appropriately allocating management resources to safety investment is a vital issue for corporate management as international competition intensifies. Understanding the priority of safety investment in a rational way helps achieve this objective.In this study, we targeted an acrylonitrile plant. First, Dow Chemical's Fire and Explosion Index (F&EI) identified the reaction process as having the greatest physical risk. We evaluated the severity of accidents in the reaction process using the Process Safety Metrics advocated by the Center for Chemical Process Safety (CCPS); however, this index does not express damages a company actually experience. To solve this problem, we proposed a new metric that adds indirect cost to CCPS metrics. We adopted fault tree analysis (FTA) as a risk assessment method. In identifying top events and basic events, we attempted to improve the completeness of risk identification by considering accidents from the past, actual plant operation and equipment characteristics, natural disasters, and cyber-attacks and terrorist attacks. Consequently, we identified the top events with high priority in handling because of serious accidents as fire/explosion outside the reactor, fire/explosion inside the reactor, and reactor destruction. The new CCPS evaluation index proposed in this study found that fire and explosion outside the reactor has the highest severity. We considered the creation of the fault tree (FT) diagram of the top event, estimating the occurrence probability, and identifying the risk reduction part and capital investment aimed at risk reduction. As an economically feasible selection method for risk reduction investment, using the difference in loss amounts before and after safety investments indicated investment priority.     

A risk reduction approach for academic research labs: A case study on naphthenic corrosion

Academic research and development (R&D) labs are a significant part of academic life. But there can be physical, environmental, and experiment quality risks associated to this activity. Academic labs can present specific experiments, which have associated risks for researchers. Academic labs are also characterized by a high turnover of students and many of them are not fully aware of the level of physical and environmental risks of their activity. Accidents in academic labs with injuries and loss of life are facts that have to be tackled through risk management approaches. The objective of this paper is to present an integrated management approach, tackling risk management and analysis methods. HAZOP (Hazard and Operability Study) and PFMEA (Process Failure Mode and Effects Analysis) enabled, respectively, the analysis of safety and environmental risks. By quantifying the level of risk according to the type of experiment and the research context, it is possible to provide safety to the system. The resulting Digital Poka-Yoke – a mistake-proofing approach – has brought about the desired quality of results in experiments. The proposed approach was validated through a case study monitoring naphthenic corrosion experiments conducted by the Lab of Surface Electrochemistry and Corrosion (LSEC) at the Federal University of Paraná (UFPR). As a consequence, this approach is currently in use at this lab.     

Risk assessment of sour gas inter-phase onshore pipeline using ANN and fuzzy inference system – Case study: The south pars gas field

Nowadays, pipelines have been extensively used for transporting oil and gas for long distances. Therefore, their risk assessment could help to identify the associated hazards and take necessary actions to eliminate or reduce the risk. In the present research, an artificial neural network (ANN) and a fuzzy inference system (FIS) were used to prepare a new model for pipeline risk assessment with higher accuracy. To reach this objective, the Muhlbauer method, as a common method for oil and gas pipeline risk assessment, was used for determining important and influential factors in the pipeline performance. Mamdani fuzzy model was developed in Matlab software by considering expert knowledge. The outcomes of this model were used to develop an ANN. To verify the developed model, the inter-phase shore pipe of phase 9–10 refinery in the South Pars Gas field was considered as a case study. The results showed that the proposed model gives a higher level of accuracy, precision, and reliability in terms of pipe risk assessment.     

Improvements on Flood Alleviation in Germany: Lessons Learned from the Elbe Flood in August 2002

The increase in damage due to natural disasters is directly related to the number of people who live and work in hazardous areas and continuously accumulate assets. Therefore, land use planning authorities have to manage effectively the establishment and development of settlements in flood-prone areas in order to avoid the further increase of vulnerable assets. Germany faced major destruction during the flood in August 2002 in the Elbe and Danube catchments, and many changes have been suggested in the existing German water and planning regulations. This article presents some findings of a “Lessons Learned” study that was carried out in the aftermath of the flood and discusses the following topics: 1) the establishment of comprehensive hazard maps and flood protection concepts, 2) the harmonization of regulations of flood protection at the federal level, 3) the communication of the flood hazard and awareness strategies, and 4) how damage potential can be minimized through measures of area precaution such as resettlement and risk-adapted land use. Although attempts towards a coordinated and harmonized creation of flood hazard maps and concepts have been made, there is still no uniform strategy at all planning levels and for all states (Lae nder) of the Federal Republic of Germany. The development and communication of possible mitigation strategies for “unthinkable extreme events” beyond the common safety level of a 100-year flood are needed. In order to establish a sustainable and integrated flood risk management, interdisciplinary and catchment-based approaches are needed.     

Incompatible Land Uses and the Topology of Cumulative Risk

The extensive literature on environmental justice has, by now, well defined the essential ingredients of cumulative risk, namely, incompatible land uses and vulnerability. Most problematic is the case when risk is produced by a large aggregation of small sources of air toxics. In this article, we test these notions in an area of Southern California, Southeast Los Angeles (SELA), which has come to be known as Asthmatown. Developing a rapid risk mapping protocol, we scan the neighborhood for small potential sources of air toxics and find, literally, hundreds of small point sources within a 2-mile radius, interspersed with residences. We also map the estimated cancer risks and noncancer hazard indices across the landscape. We find that, indeed, such large aggregations of even small, nondominant sources of air toxics can produce markedly elevated levels of risk. In this study, the risk profiles show additional cancer risks of up to 800 in a million and noncancer hazard indices of up to 200 in SELA due to the agglomeration of small point sources. This is significant (for example, estimates of the average regional point-source-related cancer risk range from 125 to 200 in a million). Most importantly, if we were to talk about the risk contour as if they were geological structures, we would observe not only a handful of distinct peaks, but a general “mountain range” running all throughout the study area, which underscores the ubiquity of risk in SELA. Just as cumulative risk has deeply embedded itself into the fabric of the place, so, too, must intervention seek to embed strategies into the institutions and practices of SELA. This has implications for advocacy, as seen in a recently initiated participatory action research project aimed at building health research capacities into the community in keeping with an ethic of care.     

含氮生物降解促进剂对土壤吸附正十六烷的影响

选用正十六烷模拟润滑油,通过振荡平衡实验,考察了两种含氮脂肪酸型生物降解促进剂（甲基二乙醇胺油酸酯（MDEAO）和油酸二乙醇酰胺（ODEA））对水土体系中正十六烷吸附行为的影响。实验结果表明：正十六烷在水土体系中的有机质标化分配系数与土壤种类无关,与生物降解促进剂种类有关;土壤对正十六烷的吸附过程更符合Freundlich等温吸附模型;MDEAO的临界胶束浓度为2.0 mg/L,对土壤吸附正十六烷有一定的促进作用,ODEA的临界胶束浓度为0.7 mg/L,形成的胶束对正十六烷的增溶效果明显,促进了正十六烷在土壤中的解吸。     

某地下大型商业建筑防火分隔方案设计和评估

针对某地下大型商业建筑消防设计在防火分隔方面存在的问题,分析几种常用防火分隔方法的适用性,初步设计几种防火分隔替代方案.采用建筑防火性能化设计思想,分析替代方案所应达到的安全目标,利用火灾动力学模拟软件FDS评估这些方案的分隔效果,给出火灾时防火卷帘迎火面和背火面的温度发展曲线.数值模拟结果表明防火分隔方案3能够达到防火墙的分隔效果,满足该建筑的消防安全要求.     

Methods for integrated assessment

Integrated assessment is an approach that seeks to involve all disciplines in policy-relevant assessment. The process aims to encompass environmental science, technology and policy problems. The aim is to establish an overview of the environmental issue in question that attempts to avoid the mistakes of the past associated with narrow, one-sided or unidimensional approaches. A number of methods are available for such assessments. However, they are also subject to a number of limitations, difficulties and dilemmas. Integrated methods are inherently complicated and the tradition is that only experts are involved. New more inclusionary procedures have to be devised in order to involve all stakeholders. They have to be involved in the framing of the issue and in the value judgements associated with the approach. The dilemmas cannot be solved by integrated approaches, but they can be mitigated via proper identification, analysis and evaluation of the gains and losses involved. In structuring the analysis the existence of ignorance has to be accounted for and communicated to the managers and the political decision makers. The ignorance/uncertainty aspects can be partially accommodated for via an intensification of feasible monitoring and research so as to minimise the risks of unpleasant surprises. Electronic Publication