Practices,barriers and benefits of risk management process in building services costs estimation: comment

This note is a comment on Mok, C.K., Rao Tummala, V.M. and Leung, H.M. (1997) Practices, barriers and benefits of risk management process in building services cost estimation, Construction Management and Economics, 15 (2), 161–75, which describes research into the risk perceptions and risk management practices of building services engineers in Hong Kong. The note questions statements made in the paper and parts of the research design and data analyses.     

Private sector participation in infrastructure projects: a methodology to analyse viability of BOT

Many developing countries are now attempting to finance new infrastructure projects through private sector participation. This paper outlines a methodology based on financial and risk analyses that a government or a government utility can use to analyse the viability of private sector participation in new infrastructure projects. The water supply projects in Sri Lanka are used for the case study to outline the methodology. Financial analyses of a bulk water supply project and a water distribution project are carried out to estimate subsidy percentages that are required to make the projects viable, using a model developed for the investment analysis of all types of infrastructure project. This analysis looks at four pricing options for the bulk supply project, and sixteen procurement options for the distribution project, from the view point of the utility, for three cases of non-revenue water (35% as base case, 50% and 25% as extreme cases). The risk analysis takes into account the risk and uncertainty in non-revenue water, cost and demand estimates, rate of debt and forecasts of escalation. These analyses show that the best option for the utility is to obtain both bulk supply and distribution projects through private sector participation using BOT arrangements.     

Non‐destructive investigation

So‐called ‘dynamic'or ‘counterflow'insulation systems have already been installed in buildings in France and Sweden for which significant improvements over ‘classic’ insulation methods have been reported. Here, the authors describe a French study, including full‐scale laboratory tests, into the actual efficiency of a ‘permeodynamic’ version. A theoretical model has been developed from which to derive thermal efficiency values, and is compared with the test results. The limits of such dynamic systems, and their most feasible applications, are then discussed. The main conclusion is that conventional insulation techniques remain competitive for houses, but permeodynamic systems offer greater possibilities for industrial buildings.     

An empirical investigation on how portfolio risk management influences project portfolio success

Project risk management is recognized as essential in order to cope with the challenges arising from the environment. Literature suggests a portfolio-wide perspective for managing risks in project portfolios. However, research on risk management and its success in a project portfolio context is scarce. This study examines how portfolio risk management influences project portfolio success. Using a sample of 176 firms, this study provides evidence that portfolio risk identification, the formalization of the portfolio risk management process, and risk management culture directly influence risk transparency, whereas risk prevention, risk monitoring, and the integration of risk management into project portfolio management are directly connected to risk coping capacity. The findings also suggest that both risk transparency and risk coping capacity have a direct impact on project portfolio success. However, the results did not confirm the hypothesis that risk transparency and risk coping capacity have a complementary effect on success. Implications for scholars and project portfolio managers are discussed.     

Implementation constraints in social enterprise and community Public Private Partnerships

Public Private Partnership (PPP) employs private sector expertise and skill to provide public goods and services. We examine three community PPP projects to identify critical success factors of the project outcomes. Two conclusions particularly stand out: first, the project must be aligned with both the public and private parties' business and service plans, and second, appropriate management structures and procedures must be established for obtaining this alignment. The latter effect recognizes the need to implement appropriate project governance practices including management discipline and expertise. We investigate these ideas further and present specific guidelines for PPP project design and implementation.     

文化遗产的危机传播——以汶川地震与海地地震后文化遗产的抢救、保护为例

该文首先指出在文化遗产保护中,风险准备与危机管理是非常重要的部分,它显示了当代文化遗产保护开始更为重视预防而非治疗,然后指出危机传播是文化遗产的危机管理的关键环节,其中遗产保护专家、学者发挥了重要作用.最后,以汶川地震和海地地震后文化遗产的抢救和保护为例,分析了危机传播对于促进公众参与和文化遗产保护的重要作用.     

同塔多回输电线路杆塔可靠指标及失效概率分析

输电线路杆塔结构可靠指标及失效概率的分析研究,目前已经广泛应用于实际工程当中,本文着重研究了500kV同塔四回输电线路杆塔的可靠指标及失效概率。对于风荷载占控制因素的杆塔结构,本文研究了可靠指标计算参数组合对于杆塔失效概率的影响,同时计算了500kV同塔四回典型杆塔的可靠指标及失效概率,提出基于输电杆塔可靠度理论的杆塔风险规避的建议。     

A HUMAN RELIABILITY ANALYSIS OF REINFORCED CONCRETE BEAM CONSTRUCTION

A significant proportion of performance failures (e.g., structural failure, cost overruns, delays) are due to human error in the construction of in-situ reinforced concrete elements. A Human Reliability Analysis (HRA) model has been developed to simulate the effect of human error on the construction of a reinforced concrete beam. The proposed HRA model incorporates the effect of (i) initial errors (i.e., before engineering inspections) and (ii) errors remaining after engineering inspections. The following typical construction tasks are considered: number and size of reinforcing bars, effective depth of steel reinforcing, beam width, and quality of concrete mix. Human performance models are described for each of these microtasks. It was found that human error leads to a significant loss of structural safety. It was also shown that engineering inspections significantly increased structural reliability, but the resulting structural reliability was still an order of magnitude lower than "nominal" estimates of structural reliability.     

Risk-informed condition assessment of civil infrastructure: state of practice and research issues

Civil infrastructure in the United States is at risk from aging, leading to structural deterioration of bridges, buildings, and other facilities from aggressive chemical attack, corrosion, and other physical mechanisms. Decisions regarding maintenance, rehabilitation and other requirements for continued utilization of a facility should be supported by quantitative evidence that aging has not caused structural strength or stiffness to deteriorate to the point where the capacity of the system to withstand or mitigate future extreme events is impaired. Current codes of practice provide little guidance for the proper evaluation of existing facilities for continued service, since their focus is on new construction. Rehabilitation investments should be aimed at maximizing the likelihood of successful future performance at minimum costs. Probabilistic risk analysis methods can provide quantitative tools for the management of uncertainty in condition assessment and are an essential ingredient of risk-informed management decisions. Such tools are data-intensive and require improved physical models of deterioration processes to realize their full potential in facility risk management.     

基于数据包络分析的调速阀关键特性包络方法研究

在介绍某典型液压阀件调速阀结构原理的基础上,根据其工作原理和平衡方程提炼出影响调速阀压力补偿性能的两个关键特性。在生产过程中采集多个成功产品样本的关键特性数据,运用过程控制图和3σ数理统计方法,通过数据包络分析,确定了这两个关键特性的包络区域。该研究可用于对产品关键特性的风险控制及管理分析。