基于缓冲区和挣值分析的项目成本与进度风险预警

为弥补挣值分析法不具有对项目成本与进度风险量进行测评的缺陷,在挣值分析法的基础上,提出了运用缓冲区定期监测项目成本与进度风险动态变化的定量方法。该方法定义了项目成本与时间的动态缓冲区,用于表示项目成本与工期在受控范围内的变化量,并运用蒙特卡罗仿真法获取动态缓冲区尺寸;在此基础上,结合挣值分析指标,构建了项目成本与进度风险动态预警指标,对预警指标值的范围进行划分与说明。并以某弹体分系统中尾段子系统初样研制项目为例演示了该方法的使用过程,表明该方法具有良好的有效性与可操作性。     

Improving project forecast accuracy by integrating earned value management with exponential smoothing and reference class forecasting

In this paper, the earned value management (EVM) project control methodology is integrated with the exponential smoothing forecasting approach. This results in an extension of the known EVM and earned schedule (ES) cost and time forecasting formulas. A clear correspondence between the established approaches and the newly introduced method – called the XSM – is identified, which could facilitate future implementation. More specifically, only one smoothing parameter is needed to calculate the enhanced EVM performance factor. Moreover, this parameter can be dynamically adjusted during project progress based on information of past performance and/or anticipated management actions. Additionally, the reference class forecasting (RCF) technique can be incorporated into the XSM. Results from 23 real-life projects show that, for both time and cost forecasting, the XSM exhibits a considerable overall performance improvement with respect to the most accurate project forecasting methods identified by previous research, especially when incorporating the RCF concept.     

Measuring the efficiency of project control using fictitious and empirical project data

Dynamic scheduling refers to the integration of three important phases in the life cycle of a project: baseline scheduling, schedule risk analysis and project control. In this paper, the efficiency of controlling a project is measured and evaluated using a Monte-Carlo simulation study on fictitious and empirical project data. In the study, the construction of a project baseline schedule acts as a point-of-reference for the schedule risk analysis and project control phases. The sensitivity information obtained by the schedule risk analyses (SRA) and the earned value management (EVM) information obtained during project control serve as early warning control parameters that trigger corrective actions to bring projects back on track in case of problems. The focus in this paper lies on the time performance of a project, and not on the prediction and controlling of the project costs.     

基于改进挣值方法的项目完工时间、成本预测

挣值管理（EVM）方法的主要功能是项目执行绩效评价和项目完工趋势预测,该方法在使用时未考虑非关键路线工序对项目预测的影响,此外成本绩效的计算以假定工期不变为前提,上述情况容易造成绩效指标不能准确反映项目进展问题。同时,由于该方法没有考虑工序时间和成本的分布特征,预测项目完工时间和成本的结果为单一的点估计值,准确性无法预估。在构建项目工序的成本/进度经验分布的基础上,对传统 EVM 指标进行了改进,提出基于蒙特卡洛仿真模拟预测项目完工时间和成本的区间及概率,为项目完工风险估计提供可靠依据。     

EDM: Earned Duration Management,a new approach to schedule performance management and measurement

The concept of schedule monitoring and control as one of the most important functions of project and program management has not been fully exploited. One possible explanation could be the dominance of the Earned Value Management System (EVMS, also known as EVM). EVM was originally developed as a cost management and control tool which was extended to track the schedule as well. EVM and its derivatives (e.g. Earned Schedule) use cost as a proxy to measure schedule performance to control the duration of the project. While there is a correlation between schedule, cost, quality, and scope of a project, using cost to control duration has proven to be misleading. In contrast to Earned Value and Earned Schedule, the authors have developed the Earned Duration Management (EDM) in which they have decoupled schedule and cost performance measures and developed a number of indices to measure progress and performance of schedule and cost, as well as the efficacy and efficiency of the plan at any level of the project. These new indices are easy to understand, have wider applications, and can be used by contractors, clients and the scheduling offices to assess and measure schedule performance. The newly developed duration performance measures are all schedule-based and can be used for forecasting the finish date of the project.     

论挣值法在项目进度管理中的应用

项目的进度管理是项目管理的三大目标之一,进度、投资、质量三者互相约束,相辅相成。挣值法是一种先进的进度测量技术,其目的就是比较项目实际与计划的差异,关注的是计划中的各个项目任务,在内容、时间、质量、成本等方面与计划的差异情况,然后根据这些差异,可以对项目中剩余的任务进行预测和调整。本文结合项目管理的实际经验讨论挣值法在项目管理中的应用。     

A fuzzy approach for the earned value management

The earned value technique is a crucial technique in analyzing and controlling the performance of a project which allows a more accurate measurement of both the performance and the progress of a project. This paper presents a new fuzzy-based earned value model with the advantage of developing and analyzing the earned value indices, and the time and the cost estimates at completion under uncertainty. As the uncertainty is inherent in real-life activities, the developed model is very useful in evaluating the progress of a project where uncertainty arises. A small example illustrates how the new model can be implemented in reality.     

A time-dependent earned value model for software projects

This paper proposes a formal method for including time dependence into Earned Value (EV) management. The model requires three parameters, which map directly to the fundamental “triple constraint” of scope, cost, and schedule: the reject rate of activities, the cost overrun parameter, and the time to repair the rejected activities. Time dependent expressions for the planned value, earned value, and actual cost are derived, along with the cost performance index (CPI) and schedule performance index (SPI). The model is built on the well-established Putnam–Norden–Rayleigh (PNR) labor rate profile, which is a useful representation for large software projects. We apply the model to a well-known software dataset, demonstrating how to estimate the project's final cost, which converges faster to the correct answer with less variability than standard Estimate-at-Completion (EAC) calculations. The model also accurately predicts the required revised labor profile and the new schedule.     

基于改进挣值法的工程项目进度优化研究

"挣值法"作为一种项目管理技术由于自身的缺陷与不足不能直接应用于工程项目的进度优化,需要进行改进与拓展。针对项目进度优化的具体问题,对"挣值法"进行了引入关键线路和扰动参数的改进与拓展,同时提出了运用改进后"挣值法"进行工期预测的计算公式与工期扰动参数估算公式。改进后的"挣值法"可以理清项目进度偏差的来源与进一步提高对项目完工工期预测的准确度,为后续项目进度优化过程中制定措施修正进度偏差与适当压缩工期提供参考。研究目的在于提高"挣值法"应用于工程项目进度优化的适用度。最后用曲线图对引入关键线路法、扰动参数后改进的挣值管理模型进行了阐释说明,并给出了一个具体使用改进后"挣值法"的案例。     

A fuzzy approach for the earned value management

The Earned Value technique is a crucial technique in analyzing and controlling the performance of a project which allows a more accurate measurement of both the performance and the progress of a project. This paper presents a new fuzzy-based earned value model with the advantage of developing and analyzing the earned value indices, and the time and the cost estimates at completion under uncertainty. As the uncertainty is inherent in real-life activities, the developed model is very useful in evaluating the progress of a project where uncertainty arises. A small example illustrates how the new model can be implemented in reality.     

Overlapping design and construction activities and an optimization approach to minimize rework

Construction industry often faces challenge to complete project in minimum possible time. Overlapping design and construction activities with early information from the precedent activities shortens project completion with the expense of rework in downstream design and construction activities. However, the expected amount of rework must be properly quantified to decide on the overlapping strategy. This study presents an integrated framework to overlap design and construction activities using the concepts of upstream evaluation and downstream sensitivity characteristics and develops a simulation model in order to ascertain project performance in terms of total project duration and expected amount of rework. The results indicate that reduction in project duration and expected rework amount vary based on the accuracy of upstream early information and sensitivity of downstream activities. Moreover, unplanned overlapping may not necessarily reduce project duration but may result in excessive design and construction rework which can be very costly. This study also describes a decision-making framework to optimize project schedule with minimal rework. The search for an optimal overlapping strategy is carried out using an Overlapping Strategy Matrix (OSM) with the genetic algorithm (GA) to eliminate unnecessary rework. The proposed optimization method minimizes the expected amount of rework while maintaining the project completion contract date and provides an effective means to decide on the overlapping strategy.     

基于关键路径的项目进度挣值分析

挣值管理是现代项目管理中的一种有效方法,在建设项目中的应用已比较普遍,指出了传统挣值分析方法在项目进度分析中存在的不足,研究了关键路径法与挣值法的集成应用,提出了基于关键路径的挣值分析方法.     

A model to control environmental performance of project execution process based on greenhouse gas emissions using earned value management

In response to recent climate change, which is believed to be attributed to the release of greenhouse gas (GHG) emissions, many countries are placing CO2 abatement programs such as carbon tax and cap-and-trade. Projects do have a significant share in GHGs and therefore their environmental performance, like their schedule and cost performance, should be monitored and controlled. Although many large projects would pass an environmental assessment in the project evaluation phase, the issue of environmental performance monitoring during the project execution phase has not been addressed in project management methodologies. The objective of this paper is to develop a model to estimate project GHG emissions, and to measure project GHG performance using the developed metrics, which can be used at any point in time over the life of a project. A comprehensive study is conducted to collect information on GHG emission factors of various project activity data (such as material use, energy and fuel consumption, transportation, etc.), and a user form interface is developed to calculate the total GHG of an activity. Also, a breakdown structure is proposed which supports managing all the project GHG accounts. The monitoring and control model is formulated based on the logic used in earned value management (EVM) methodology. The proposed model is then implemented to a work package of a real construction project. The results present the project initial GHG plan and show that the model is able to calculate project GHG variance by the reporting date and predict project final GHG based on a project GHG performance index. The method presented in this paper is general and can be applied to any type of projects in an organization that aims to reduce its carbon footprint. The same structure can be applied to monitor and control any other environmental impact associated with project execution process.     

Monitoring project duration and cost in a construction project by applying statistical quality control charts

The earned value is a leading technique in monitoring and analyzing project performance and project progress. Although, it allows exact measurement of project progress, and can uncover any time and cost deviations from the plan, its capability in reporting accepted level of deviation is not well studied. This study presented an approach to overcome this limitation by applying statistical quality control charts to monitor earned value indices. For this purpose, project time and cost performance indices of a real construction project were monitored regularly on individual control charts. The results were quite promising, and not only competed well against traditional approaches, but also enhanced team's knowledge of project performance. At the end, it was concluded that the proposed approach improves substantially the project controlling scheme and enhances the capability of earned value technique.     

改进挣值法在工程项目综合绩效评价中的应用

为了使传统挣值法能够对工程项目的实施情况进行更详尽的偏差分析,在辨析基本参数（BCWS、BCWP、ACWP）相关概念的基础上,按照将原计划工作内容与新增工作内容进行区别调整的逻辑,提出了挣值法的新基本参数与偏差分析指标。并通过一个算例对改进后的挣值法的偏差指标进行运用分析,从而增强了挣值法对项目进度绩效和费用绩效两方面的偏差分析能力。     

赢得值与关键路径法在项目上的有效应用探析

介绍了工程项目进度量化管理方法,并对赢得值与关键路径法在工程项目上有效应用的问题进行了研究,提出了赢得值与关键路径法相结合对项目实施量化控制的方法和注意事项,以更好的控制项目进度。     

Intelligent monitoring and evaluation for the prefabricated construction schedule

The prefabricated building construction (PBC) project is sensitive to uncertainties due to the highly required coordination and interdependency among the installation activities, which may cause progress delay. Hence, it is necessary to monitor the installation progress and evaluate the schedule in terms of the project duration to take proactive control actions to avoid actual project delay. This study focuses on intelligent monitoring and evaluation for the PBC schedule by combining the computer vision-based (CVB) technology, a weighted kernel density estimation (WKDE) method, and the earned duration management (EDM) method. Intelligent and real-time far-field detection of the prefabricated components (PCs) and workers is achieved through the CVB technology, which is, respectively, used to measure the progress status of the PC installation works and other manual works by means of the WKDE method. The PBC project duration is then predicted based on the monitored progress status to evaluate the schedule through the EDM method. The proposed intelligent schedule monitoring and evaluation method have been illustrated and justified through a field application. This study contributes to achieving intelligent schedule monitoring and evaluation for the PBC project.     

基于灰色 Verhulst 和EVM 模型的项目进度—成本绩效预测研究

传统挣值管理以进度和成本绩效指数为基础进行完工成本预测,在项目实施的早期其预测值与实际数据会存在较大偏差。因此,项目实施的早期,项目管理团队应侧重对进度和成本绩效趋势进行短期预测。在介绍挣值管理和灰色Verhulst 模型的基础上,提出采用Verhulst 模型对项目的实际成本和挣值进行预测,并计算进度和成本偏差,通过比较借此发现进度和成本绩效的发展趋势。最后结合具体案例详细介绍了建立灰色Verhulst 模型以及利用此模型进行预测的步骤。案例表明该方法是可行和有效的。     

浅析项目管理的主要控制要素

介绍了工程项目管理的主要控制要素及主要目标，针对成本／进度综合控制方法进行了详细阐述，重点论述了赢得值分析法的步骤，得出了赢得值分析法是工程项目／成本进度综合度量和监控的有效方法，以推广该方法。     

改进的挣值技术在厂房建设中的应用研究

项目管理的核心要素是进度、成本、质量,传统的挣值法仅仅体现了前两者而不全面。为了将单一进度和成本的二元挣值管理提升为三元素挣值综合项目管理,本文采用引入质量参数的改进的挣值技术的方法,以陶瓷厂房建设项目为例分析了引入质量参数后的包含工程进度、成本、质量三元素的挣值法的实施情况,提供了改进后的挣值理论在工程建设中的可操作性,为改进后的挣值技术在项目管理中的应用提供了借鉴。