Geostatistical Modeling of Uncertainty for the Risk Analysis of a Contaminated Site

This work is a study of multivariate simulations of pollutants to assess the sampling uncertainty for the risk analysis of a contaminated site. The study started from data collected for a remediation project of a steel- works in northern Italy. The soil samples were taken from boreholes excavated a few years ago and analyzed by a chemical laboratory. The data set comprises concentrations of several pollutants, from which a subset of ten organic and inorganic compounds were selected. The first part of study is a univariate and bivariate sta- tistical analysis of the data. All data were spatially analyzed and transformed to the Gaussian space so as to reduce the effects of extreme high values due to contaminant hot spots and the requirements of Gaussian simulation procedures. The variography analysis quantified spatial correlation and cross-correlations, which led to a hypothesized linear model of coregionalization for all variables. Geostatistical simulation methods were applied to assess the uncertainty. Two types of simulations were performed: correlation correction of univariate sequential Gaussian simulations (SGS), and sequential Gaussian co-simulations (SGCOS). The outputs from the correlation correction simulations and SGCOS were analyzed and grade-tonnage curves were produced to assess basic environmental risk.

Operation safety risk analysis method of hydropower project considering time-dependent effect

In order to consider the time-dependent characteristic of risk factors of hydropower project,the method of stochastic process simulating structure resistance and load effect is adopted.On the basis of analyzing the structure characteristics and mode of operation,the operation safety risk rate assessment model of hydropower project is established on the comprehensive application of the improved analytic hierarchy process,the time-dependent reliability theory and the risk rate threshold.A scheme to demonstrate the time-dependent risk rate assessment method for an example of the earth-rock dam is particularly implemented by the proposed approach.The example shows that operation safety risk rate is closely related to both the service period and design standard;considering the effect of time-dependent,the risk rate increases with time and the intersection of them reflects the technical service life of structures.It could provide scientific basis for the operation safety and risk decision of the hydropower project by predicting the trend of risk rate via this model.

Impacts of the Financial Factors on Schedule Delays Risk of the International Contracting Projects: Evidence from Highway BOT Pro-jects in Vietnam

Vietnam has become a major market for construction enterprises from East Asian countries, especially from China, to participate in international project contracting, but serious schedule delays have important adverse effects on local government and foreign investment companies. Based on international engineering contracting mode of Vietnam highway BOT construction projects, we discussed the drive financial factors of schedule delays, using the methods of exploratory factor analysis and questionnaire survey, and evaluated the effects of various factors which are through regression analysis. The empirical results show that the five categories of financial factors, including the policy change, slow payment, financial mismanagement, financial market changes and lack of fiscal, have significant effects on schedule delay. Furtherly, we suggested that strengthening policy research and improving financial management ability should be used to reduce the influence of relevant financial factors on schedule delay, to improve the profitability of international businesses and the motivation of foreign enterprises to participate in Vietnam highway project.

Project Risk in the Age of Artificial Intelligence:A Metanetwork Assessment of Behavior-Centric Intangible Risks

Industrial projects can be viewed as complex sociotechnical systems(e.g.,human agents interacting with technology)where cause-and-effect relationships do not necessarily occur in time-and-space proximity.For this work,metanetwork(e.g.,a network of networks)analysis was applied to emergent behavior-centric intangible risks(BCIRs)in a portfolio of projects in the energy sector.A user-friendly framework is proposed to identify and quantitatively assess BCIRs,along with the conditions that initiate them throughout the project development cycle.The underlying hypothesis is a structured approach to identifying,assessing,and proactively addressing BCIRs that have the potential to improve a project team’s ability to meet its objectives.While we build upon Rasmussen’s dynamic safety model and address the need for a framework to assess causal factors that influence behaviors in the context of an energy-sector project,we do this with a view to a future where technology(e.g.,artificial intelligence(AI),automation,robotics,etc.)will play an ever-increasing role.The proposed framework is presented as tested in a live project portfolio setting where organizational modifications were identified,simulated,and implemented.One particular dimension of the analysis,the issue of authority without responsibility,is also discussed.The results of this empirical assessment were further validated by an industry panel of subject-matter experts(SMEs).

Applying Fuzzy Rule-Based System on FMEA to Assess the Risks on Project-Based Software Engineering Education

Project-based learning has been in widespread use in education. However, project managers are unaware of the students’ lack of experience and treat them as if they were professional staff. This paper proposes the application of a fuzzy failure mode and effects analysis model for project-based software engineering education. This method integrates the fuzzy rule-based system with learning agents. The agents construct the membership function from historical data. Data are processed by a clustering process that facilitates the construction of the membership function. It helps students who lack experience in risk assessment to develop their expertise in that skill. The paper also suggests a classification technique for a fuzzy rule-based system that can be used to judge risk based on a fuzzy inference system. The student project will thus be further enhanced with respect to risk assessment. We then discuss the design of experiments to verify the proposed model.

Cost Risk Appraisal： An Application of Project RiskManagement Process in Libyan Construction Projects

Projects delay and cost overrun have become general facts in the construction industry. Project cost risk analysis considers the different costs associated with a project and focuses on the uncertainties and risks that may affect these costs. An implementation of PRM （project risk management） process on regional construction project has been carried out to maximize the likelihood of project meeting its objectives within its constraints. Qualitative and quantitative risk analyses have been carried out. The qualitative analysis is presented in a table that shows top ranked risks in Libyan construction projects based on probability-impact grid technique. In quantitative risk analyses, Mont Carlo simulation technique has been conducted to quantify and evaluate the overall level of risk exposure associated with the project completion cost. A project simulation uses a model that translates cost uncertainties into their potential impact on project objectives. A frequency curve model that represents simulation results of project completion costs has been constructed. The frequency curve model shows all possible outcomes of expected project cost at different probabilities. Project manager or decision maker can select the appropriate project budget. If a probability of 0.95 confident project budget is selected that means cost overrun risk can be minimized to a probability of 0.05. It is very helpful for project manager to take decisions based on information that shows project completion cost and its associated probability rather than usin single information of estimated cost.

Research on Subcontractor Risk of EPC Hydropower Project in Vietnam

Engineering, procurement and construction (EPC) contracts are becoming the most popular form to undertake construction works on large-scale hydropower projects.?The EPC general contractors in Vietnam have been coped with lots of difficulties during the construction phase of hydropower projects, resulting in significant schedule delays and cost overrun. One of the reasons is poor Subcontractors capacity.?In order to overcome above, the current study attempts?to research on identification and control Subcontractors risks of delay process of EPC hydropower project in Vietnam.?Through summarizing international research achievements of previous researches relating on EPC hydropower projects combining with analysis characteristics of developing construction of EPC hydropower projects in Vietnam, the current study pointed out all kinds of subcontractor risk of delay process of EPC hydropower project in Vietnam;?a questionnaire with 18 risk elements was designed and then delivered to experts in EPC hydropower project management area. Based on the risk model, 11 main risk elements were identified which can be categorized into 3 groups.?Lastly, the current study proposed suggestions to reduce or avoid risks as well as approach to control risks.?Furthermore, the findings of this study can be a good managerial reference for project management teams who are working in other countries that have similar economic and investment environment to Vietnam to get their EPC construction project completed on schedule, thus ensuring the benefits to the government, the investor, the contractor, and the parties involved.

Research on Quality Risk of EPC Hydropower Projects in Vietnam

Engineering, procurement and construction (EPC) contracts are on the way to become the most usual form of contracting applied by the private sector to undertake construction works on large scale Hydropower projects. If EPC contract management is not implemented and controlled properly. Quality is the first important factor for any contractors who involve in the hydropower project execution. The purpose of this study is to investigate and evaluate risks causing not good quality of EPC hydropower projects in Vietnam. In addition, the study also provided the recommendations for project practitioners to mitigate the impacts of those identified risks. The findings of this study can be a good managerial reference for project management teams who are working in other countries that have similar economic and investment environments to Vietnam to get their EPC construction project completed on quality, thus will ensuring the benefits to the government, the investors, the contractors, and the parties involved.

Program Evaluation and Review Technique (PERT) in Construction Schedule Risk Assessment

Construction project scheduling is one of the most critical factors for project success measurement.Not only for the project planning but for construction process management,the scheduling is the basic tool for communication between the owner and the project manager.By developing the schedule before the project starts,the owner knows in advance that the expected timeline of the project.By preparing construction process scheduling,the owner and general contractor can better manage the subcontractors,sub-trades progress,materials storage and deliveries,labors schedule and equipment set up which will eventually save time,money and hassle.Basically,Critical Path Method(CPM) is commonly used in the construction industry.CPM is a deterministic method that assumes that through the network,there is at least one path that determines the project duration and that the path is the critical path.CPM does not consider the uncertainty in the activities;rather it assumes that each activity can be finished in the given situation.Program Evaluation and Review Technique(PERT) is a stochastic technique which is based on the assumption that the duration of a single activity can be described by a probability density function.PERT takes into account the uncertainty during the construction process and has been created out of the need to plan,schedule and control complex projects with many uncertainties.The PERT approach is stated in some books and papers,but there is no deep investigation on the application in the schedule risk assessment.This paper investigates the PERT work process and takes a valuable try on the construction schedule risk assessment by using case studies.The utilization in the estimate the construction liquidated damage with the uncertainties is performed,which also can be used in the insurance company to calculate the insurance premium.

Research on Risk Evaluation Method for International Engineering Projects

Risk evaluation is one of the important elements of international engineering project management. The risk factors of international engineering projects are systematically analyzed from multiple dimension features of the projects. The muhilayer evaluation index system for the international engineering project risk assessment is proposed and constructed, which consists of 8 I-grade indexes and 24 II-grade indexes as policy risk, market risk, resource risk, and technical scheme risk, schedule risk, funding risk, personnel risk and management risk. And then the self-evaluation and benchmarking evaluation methods are applied to evaluate the international engineering project risk, and established the corresponding mathematical models. Finally, a project evaluation example is given to illustrate the applicability and effectiveness of the mathematical models.

Analyses on schedule-cost coefficient correlation of spaceflight project based on historical statistics and its application

When analyze the uncertainty of the cost and the schedule of the spaceflight project, it is needed to know the value of the schedule-cost correlation coefficient. This paper deduces the schedule distribution, considering the effect of the cost, and proposes the estimation formula of the correlation coefficient between the in（schedule） and the cost. On the basis of the fact and Taylor expansion, the relation expression between the schedule-cost correlation coefficient and the in-schedule-cost correlation coefficient is put forward. By analyzing the value features of the estimation formula of the in-schedule-cost correlation coefficient, the general rules are proposed to ascertain the value of the schedule-cost correlation coefficient. An example is given to demonstrate how to approximately amend the schedule-cost correlation coefficient based on the historical statistics, which reveals the traditional assigned value is inaccurate. The universality of this estimation method is analyzed.

Managing project risks and uncertainties

This article considers threats to a project slipping on budget,schedule and fit-for-purpose.Threat is used here as the collective for risks（quantifiable bad things that can happen）and uncertainties（poorly or not quantifiable bad possible events）.Based on experience with projects in developing countries this review considers that（a）project slippage is due to uncertainties rather than risks,（b）while eventuation of some bad things is beyond control,managed execution and oversight are stil the primary means to keeping within budget,on time and fit-for-purpose,（c）improving project delivery is less about bigger and more complex and more about coordinated focus,effectiveness and developing thought-out heuristics,and（d）projects take longer and cost more partly because threat identification is inaccurate,the scope of identified threats is too narrow,and the threat assessment product is not integrated into overall project decision-making and execution.Almost by definition,what is poorly known is likely to cause problems.Yet it is not just the unquantifiability and intangibility of uncertainties causing project slippage,but that they are insufficiently taken into account in project planning and execution that cause budget and time overruns.Improving project performance requires purpose-driven and managed deployment of scarce seasoned professionals.This can be aided with independent oversight by deeply experienced panelists who contribute technical insights and can potentially show that diligence is seen to be done.

Estimation Method of Schedule-cost Correlation Coefficient of Spaceflight Project

To evaluate the cost risk and the schedule risk of the spaceflight project,the schedule-cost(S-C) correlation coefficient is directly appointed according to the experts' experience usually.This paper deduces SDMCU(the schedule distribution model considering the effect of the cost uncertainty),and then proposes the approximate formula to estimate the ln(S)-C correlation coefficient based on the models of SDMCU and CDMSU(the cost distribution model considering the effect of the schedule uncertainty).Furthermore,an approximate relationship expression of the S-C and the ln(S)-C correlation coefficients is put forward according to general facts and the Taylor expansion,and advanced by means of mass numerical validation is the general rule of obtaining the estimation value of the schedule-cost correlation coefficient based on the historical data.

运用Crystal Ball & MS Project实现项目进度的蒙特卡洛风险分析

通过运用Crystal Ball和MS Project软件进行蒙特卡洛模拟,对项目进度计划风险分析及实际应用进行研究和探讨,在项目管理实践中将起到非常大的作用。

Cost-Benefit Analysis of the Wuxikou Integrated Flood Management Project Considering the Effects of Flood Risk Reduction and Resettlement

Evaluation of the economic costs and benefits of flood disaster risk management projects is crucial.However,current costbenefit analyses(CBA) often lack reliable estimates of the expected loss reduction from flood control measures and ignore quantitative assessments of resettlement.To address these limitations,this study incorporated a probabilistic risk analysis method and quantitative resettlement benefits assessment into the CBA framework,using the Wuxikou Integrated Flood Management Project(WIFMP) in Jiangxi Province,China,as a case study.The direct economic benefits of flood control were estimated by integrating hydrological statistics,numerical flood inundation simulation,and quantitative damage analysis with exposure and vulnerability data.Furthermore,the resettlement benefits were quantified by measuring the annual income growth of migrants based on assumptions about household employment.Our analysis shows that the total WIFMP investment is RMB 3546.1 million yuan(USD 1=RMB 6.976 yuan),including loan principal and interest of 244.4 million yuan,and operations and maintenance of 605.5 million yuan at 2020 prices.Annual project benefits are estimated at 351.3 million yuan in flood risk reduction,155.7-191.9 million yuan from increased resettlement income,and 42.7 million yuan in power and water revenues.Considering the costs and benefits across the entire project lifecycle,the internal rate of return ranges from 13.7 to 14.2%,and the net present value ranges from 31.8 to 352.6 billion yuan.Through improved benefit estimation methodology,this research enables a more reliable and holistic evaluation of costs and benefits for flood risk management projects.It provides insights for policymakers and practitioners involved in similar projects,contributing to more informed decision making and better allocation of resources in flood disaster risk management.

Buffer Sizing Method for Constructing Stable Schedules with Duration Constraints

The assumption of static and deterministic conditions is common in the practice of construction project planning. However, at the construction phase, projects are subject to uncertainty. This may lead to serious schedule disruptions and, as a consequence, serious revisions oft.he schedule baseline. The aim of the paper is developing a method for constructing robust project schedules with a proactive procedure. Robust project scheduling allows for constructing stable schedules with time buffers introduced to cope with multiple disruptions during project execution. The method proposed by the authors, based on Monte Carlo simulation technique and mathematical programming for buffer sizing optimization, was applied to scheduling an example project. The results were compared, in terms of schedule stability, to those of the float factor heuristic procedttre.

RISK ANALYSIS OF EROSION BELOW THE DAM OF ER TEN PROJECT

The erosion risk below the dam of Er Tan project, which comes from the flood relief of the spillway and mid- dle outlet spillway, is analysed by risk analysis theory. According to the analysis results, it is imperative that the stilling pool below the dam should be adopted to protect river bed from erosion. From the view of risk-protection and economy, the Er Tan project design scheme that adopted the stilling pool is coincident with safe and economical rules. It is efficient and scientific. The erosion risk analysis method used in the paper can be used in other projects. The results are certainly of reference value and great significance for engineering design.

RISK MODEL FOR ENERGY PERFORMANCE CONTRACTING IN CORRECTIONAL FACILITIES

Energy performance contracting provides guaranteed minimum energy savings to building owners,enabling them to finance project costs using utility savings over the duration of the project.This has been an attractive project delivery method for organizations with reduced budgets for capital projects,particularly among correctional facilities which frequently have lengthy periods of deferred maintenance and ongoing building operations and maintenance concerns.This research builds on a previously developed project factors risk framework for energy service companies undertaking building retrofits.This paper proposes a risk analysis and evaluation model that includes quantitative,expert-based,and probabilistically derived information.Expected cost was used to evaluate risks over lengthy project life cycles and a new metric was developed for use in the model-expected life cycle value.Model results reveal that the most critical risk factors relate to the reduced availability of“low-hanging fruit”energy conservation measures,work scopes based on traditional design-bid-build procurement,unavailable or inaccurate facility information,facility age and current code requirements,and conducting the investment grade audit too quickly.The life cycle cost-based risk model employed in this paper is proposed as an advancement over traditional risk management methods,and it is expected to be applicable,with modification,across other municipal and state government subdomains,especially high security projects.

The Evaluation of the Integrated Risk for the South-to-North Water Transfer Project Using the Bayesian Network Theory

南水北调工程是目前我国最大的调水工程。随着工程的建设和运行,由不确定性问题引起的风险问题越来越受到关注,工程运行的风险分析也摆在管理者的面前,如何识别、评估、降低和控制风险的发生成为南水北调工程运行中的一个重要问题。本文首次将贝叶斯网络理论引入到南水北调综合风险分析中,选取东线工程宝应抽水泵站为研究对象,利用贝叶斯网络推理功能得出宝应站运行综合风险发生的概率为0.025%,风险发生的等级为"较低"。利用情景分析的方法,得出在影响综合风险的因素中,泵站的管理维护状况条件改变时,综合风险变化最大,因此需要予以重点关注。

南四湖不同起调水位汛期调水风险传导规律

南水北调东线工程通水以来,有效缓解了山东半岛等地的缺水问题,但水资源供需矛盾依然突出,汛期调水将成为解决该矛盾的方式之一。汛期调水时,湖周河道开闸泄洪,非汛期积累于河道中的污染物随水流下泄入湖,使得流域水环境风险显著增加。为科学支撑东线后续工程汛期调水水环境风险管控和探究湖区内部风险传导机制,以南水北调东线调蓄湖泊南四湖上级湖段为例,构建水环境风险空间传导分析模型,计算相邻子湖区处于不同风险状态组合的概率,定量评价汛期调水时南四湖上级湖流域水环境风险状态,探讨丰、平、枯3种水平年起调水位下水环境风险在南四湖上级湖的传导规律。结果表明:丰水年高水位调水时,南四湖上级湖水环境风险值最小,枯水年最大;高、中水位调水时,呈由低风险传导至中风险、再传导至高风险的逐步传导模式,而低水位调水时,风险由低风险直接传导至高风险;以平水年为例,白马河区至万福河区93%概率为低—中风险增强型传导、7%概率为低—高风险增强型传导。