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1.
The vast majority of the project scheduling research efforts over the past several years have concentrated on the development
of workable predictive baseline schedules, assuming complete information and a static and deterministic environment. During
execution, however, a project may be subject to numerous schedule disruptions. Proactive-reactive project scheduling procedures
try to cope with these disruptions through the combination of a proactive scheduling procedure for generating predictive baseline
schedules that are hopefully robust in that they incorporate safety time to absorb anticipated disruptions with a reactive
procedure that is invoked when a schedule breakage occurs during project execution.
In this paper we discuss the results obtained by a large experimental design set up to evaluate several predictive-reactive
resource-constrained project scheduling procedures under the composite objective of maximizing both the schedule stability
and the timely project completion probability. 相似文献
2.
考虑资源置信度的跨企业项目鲁棒性调度算法 总被引:1,自引:1,他引:0
资源不确定性高和调度鲁棒性要求高是跨企业项目调度问题的重要特征,本文采用资源置信度度量资源的不确定性,建立了考虑资源置信度约束的跨企业项目鲁棒性优化调度模型,设计了路径重连求解算法.算法以路径重连机制搜索解空间,以嵌入 的启发式时间缓冲插入算法快速生成鲁棒性调度,并可通过局部增强搜索算法进一步优化调度的鲁棒性.本文应用项目调度标准问题 库PSPLIB中大量问题实例进行了仿真实验,同两个当前具有代表性的鲁棒性项目调度算法进行了比较,实验结果表明了文中算法的有 效性与优势. 相似文献
3.
Proactive and reactive strategies for resource-constrained project scheduling with uncertain resource availabilities 总被引:3,自引:0,他引:3
Research concerning project planning under uncertainty has primarily focused on the stochastic resource-constrained project
scheduling problem (stochastic RCPSP), an extension of the basic RCPSP, in which the assumption of deterministic activity
durations is dropped. In this paper, we introduce a new variant of the RCPSP, for which the uncertainty is modeled by means
of resource availabilities that are subject to unforeseen breakdowns. Our objective is to build a robust schedule that meets
the project deadline and minimizes the schedule instability cost, defined as the expected weighted sum of the absolute deviations
between the planned and the actually realized activity starting times during project execution. We describe how stochastic
resource breakdowns can be modeled, which reaction is recommended, when a resource infeasibility occurs due to a breakdown,
and how one can protect the initial schedule from the adverse effects of potential breakdowns. An extensive computational
experiment is used to show the relative performance of the proposed proactive and reactive strategies. It is shown that protection
of the baseline schedule, coupled with intelligent schedule recovery, yields significant performance gains over the use of
deterministic scheduling approaches in a stochastic setting.
This research has been supported by project OT/03/14 of the Research Fund of K.U.Leuven, project G.0109.04 of the Research
Programme of the Fund for Scientific Research, Flanders (Belgium) (F.W.O.-Vlaanderen) and project NB/06/06 of the National
Bank of Belgium. 相似文献
4.
The multi-mode resource-constrained project scheduling problem (MRCPSP) involves the determination of a baseline schedule of the project activities, which can be executed in multiple modes, satisfying the precedence relations and resource constraints while minimizing the project duration. During the execution of the project, the baseline schedule may become infeasible due to activity duration and resource disruptions. We propose and evaluate a number of dedicated exact reactive scheduling procedures as well as a tabu search heuristic for repairing a disrupted schedule, under the assumption that no activity can be started before its baseline starting time. We report on promising computational results obtained on a set of benchmark problems. 相似文献
5.
《Computers & Industrial Engineering》2007,52(1):11-28
This paper describes new heuristic reactive project scheduling procedures that may be used to repair resource-constrained project baseline schedules that suffer from multiple activity duration disruptions during project execution. The objective is to minimize the deviations between the baseline schedule and the schedule that is actually realized.We discuss computational results obtained with priority-rule based schedule generation schemes, a sampling approach and a weighted-earliness tardiness heuristic on a set of randomly generated project instances. 相似文献
6.
Homayoun Khamooshi 《Computers & Industrial Engineering》1998,35(3-4):507-510
The purpose of this paper is twofold, first to introduce and evaluate a dynamic priority scheduling model developed in this research for solving the resource constraint project scheduling problem, second to introduce an improvement made upon the first model by cross breeding Dynamic Programming with the Dynamic Priority Scheduling Method (DPSM). The second model called Dynamic Priority Dynamic Programming Scheduling Method [(DP)2SM] aims at optimising the staged resource allocation decisions in DPSM. DPSM divides a project into phases (cycles) the length of which depend on the duration of the project and the period of clock cycle selected. The scheduling process starts by allocating resources to the first phase/cycle using a variety of policies, then the best schedule is selected based on an objective function. The process continues till all the activities are scheduled. In DPSM the interaction between phases is ignored while the decisions of each phase or cycle will affect all the remaining phases. Using (DP)2 SM it may be possible to improve the quality of a schedule and reduce the duration of a project by optimising the overall project schedule. 相似文献
7.
柔性工时约束下项目调度及其蚁群算法 总被引:1,自引:0,他引:1
针对软件工程项目调度问题,在考虑加班工时的情况下,提出了柔性工时约束下项目调度问题的数学模型,并设计了相应的蚁群算法。模型对项目人力资源的特殊性进行了分析,指出项目人力资源是一种特殊的可更新资源,在允许加班的情况下,人力资源构成特殊的柔性工时约束。针对所设计的数学模型,在并行项目进度生成机制基础上设计了蚁群算法,并通过算例进行验证与分析。 相似文献
8.
Nancy L. Mills Ph. D 《Computers & Industrial Engineering》1989,17(1-4):149-153
The development of a university sports complex requires an integrated planning, scheduling and management approach, a requirement which is underscored by the desired to overlap design and construction activities in order to complete the facility on an accelerated schedule. The analysis of the project utilizes project management techniques: development of network models, identification of critical paths, and scheduling, cost control and resource allocation considerations. The use of computerized project planning and control tools provides flexibility and enables easy modification of the plans. 相似文献
9.
10.
A two-stage-priority-rule-based algorithm for robust resource-constrained project scheduling 总被引:5,自引:0,他引:5
Traditionally, the resource-constrained project scheduling problem (RCPSP) is modeled as a static and deterministic problem and is solved with the objective of makespan minimization. However, many uncertainties, such as unpredictable increases in processing times caused by rework or supplier delays, random transportation and/or setup, may render the proposed solution obsolete. In this paper, we present a two-stage algorithm for robust resource-constrained project scheduling. The first stage of the algorithm solves the RCPSP for minimizing the makespan only using a priority-rule-based heuristic, namely an enhanced multi-pass random-biased serial schedule generation scheme. The problem is then similarly solved for maximizing the schedule robustness while considering the makespan obtained in the first stage as an acceptance threshold. Selection of the best schedule in this phase is based on one out of 12 alternative robustness predictive indicators formulated for the maximization purpose. Extensive simulation testing of the generated schedules provides strong evidence of the benefits of considering robustness of the schedules in addition to their makespans. For illustration purposes, for 10 problems from the well-known standard set J30, both robust and non-robust schedules are executed with a 10% duration increase that is applied to the same randomly picked 20% of the project activities. Over 1000 iterations per instance problem, the robust schedules display a shorter makespan in 55% of the times while the non-robust schedules are shown to be the best performing ones in only 6% of the times. 相似文献
11.
蒋晓科 《数字社区&智能家居》2011,(5)
针对当今软件项目中普遍出现的工期拖延、进度失控问题,介绍了时间管理的基本概念,接着从活动定义、活动排序、活动工期估算、进度安排、进度控制几个方面介绍了时间管理的过程。 相似文献
12.
13.
针对航空型号生产项目的特点,提出了一种综合项目工期、成本及质量等多目标的集成进度控制方法。该方法中,以集成进度控制模型为理论基础,采用M-BOM作为计划制定的基本数据源,结合WBS与分级网络计划技术产生多目标集成进度计划;运用EVM思想结合监控过程构建集成进度监控的具体方法。最后,使用自主开发的软件系统,分析了某型飞机生产项目的实例,验证了方法的有效性。 相似文献
14.
15.
The purpose of this research is to develop a new procedure for generating a proactive baseline schedule for the resource-constrained project scheduling problem. The main advantage of this new procedure is that it is completely independent of the reactive policy applied. This contrasts with the traditional methods that assume a predefined reactive policy. First, we define a new robustness measure, then we introduce a branch-and-cut method for solving a sample average approximation of our original problem. In a computational experiment, we show that our procedure outperforms two other published methods, assuming different robustness measures. 相似文献
16.
The efficient scheduling of the new product development (NPD) projects is important to reduce the required development time, and to offer the new product faster. Activity overlapping is commonly regarded as the most promising strategy to reduce product development times. However, overlapping must be well-planned by weighting the gain from the activity overlapping against the additional time for rework. The objective of this research was to develop a resource constrained scheduling methodology for NPD projects considering overlapping of activity couples. A particle swarm optimization based approach is used to schedule NPD projects that include overlapping process. The proposed PSO method is developed into a user friendly system so that the practitioners can utilize it. A real-life example of a product development project taken from the literature is used to show the efficiency of the software. 相似文献
17.
针对资源受限项目调度问题,提出了一种基于人工蜂群算法的优化方法。人工蜂群算法中每个食物源的位置代表一种项目任务的优先权序列,每个食物源的位置通过扩展串行调度机制转换成可行的调度方案,迭代中由三种人工蜂执行不同的操作来实现全局最优解的更新。实验结果表明,人工蜂群算法是求解资源受限项目调度问题的有效方法,同时扩展调度机制的引入可以加速迭代收敛的进程。 相似文献
18.
Scheduling Multi-Mode Projects under Uncertainty to Optimize Cash Flows: A Monte Carlo Ant Colony System Approach
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Project scheduling under uncertainty is a challenging field of research that has attracted increasing attention. While most existing studies only consider the single-mode project scheduling problem under uncertainty, this paper aims to deal with a more realistic model called the stochastic multi-mode resource constrained project scheduling problem with discounted cash flows (S-MRCPSPDCF). In the model, activity durations and costs are given by random variables. The objective is to find an optimal baseline schedule so that the expected net present value (NPV) of cash flows is maximized. To solve the problem, an ant colony system (ACS) based approach is designed. The algorithm dispatches a group of ants to build baseline schedules iteratively using pheromones and an expected discounted cost (EDC) heuristic. Since it is impossible to evaluate the expected NPV directly due to the presence of random variables, the algorithm adopts the Monte Carlo (MC) simulation technique. As the ACS algorithm only uses the best-so-far solution to update pheromone values, it is found that a rough simulation with a small number of random scenarios is enough for evaluation. Thus the computational cost is reduced. Experimental results on 33 instances demonstrate the effectiveness of the proposed model and the ACS approach. 相似文献
19.
Resource-constrained project scheduling with activity pre-emption assumes that activities are allowed to be interrupted and restarted later in the schedule at no extra cost. In the current paper, we extend this pre-emptive scheduling problem with setup times between activity interruptions and the possibility to schedule pre-emptive sub-parts of activities in parallel.
The contribution of the paper is twofold. First, we briefly show that an efficient exact branch-and-bound procedure from the literature to solve the resource-constrained project scheduling problem can be easily adapted to cope with our problem extensions. Second, we extensively test the impact of these pre-emptive extensions to the quality of the schedule from a makespan point-of-view. 相似文献