【作者】 卢伟倬；

【导师】 姚兵； 王要武；

【作者基本信息】 哈尔滨工业大学 ， 管理科学与工程， 2008， 博士

【摘要】 就世界范围而言,建设项目的整体管理水平还不是很高,存在生产效率低下、大量的浪费、建筑成本居高不下等问题。究其原因,缺乏明确的理论基础是阻碍建设项目管理水平进步的一个因素,精益建设理论正是为解决这一问题而产生的。目前,精益建设理论的研究在发达国家属于研究的热点问题,而我国的精益建设理论研究尚处于探索阶段,相关的理论和方法还不完善。积极探索和引入先进的精益建设理论、提高建设项目的生产效率、减少浪费、降低施工成本,极大程度地影响着我国建筑施工企业的生存与发展。基于精益建设理论,本文以工作流以及工作流的连续性为研究对象,围绕不确定工期条件下如何保证工作流的连续性、减少工作流流动过程中的浪费为核心问题展开研究,综合运用循环网络仿真技术(Cycle Operation Network, CYCLONE)、遗传算法(Genetic algorithm, GA)、四维计算机辅助设计技术(4D-CAD)、平衡线法(Line of balance, LOB)、约束理论(Theory of constraints, TOC)和可扩展标记语言(eXtensible Markup Language, XML),构建了工作流集成管理方法,实现建设项目工作流的精益管理。主要的研究工作如下:从精益建设理论流管理的角度,定义工作流以及工作流连续性的概念,工作流为不同工种的劳动力(班组)在时间和空间上的不断地流动,以完成施工任务、实现顾客需求的过程。本文将位置流和装配流涵盖于工作流的概念之内,同时,归纳了工作流流动过程中的不增值活动(浪费)。由于施工过程的可变性,以一个固定的数值表示某一施工任务的工期并不能切实地反应实际的施工状况。因此,本文基于循环网络仿真技术,提出不确定工期条件下的工作流连续性仿真模型。不确定工期条件下的工作流连续性仿真模型应用面向对象仿真和层次化建模的方法,在仿真模型中引入滞后缓冲节点以使工作流的最早开始时间延迟至指定的滞后缓冲值。模型有效性验证表明,基于循环网络的工作流仿真模型,有效地降低了工作流的直接成本和闲置时间,提高了工作流的连续性,使得施工项目工期-成本-连续性权衡最优;同时,仿真模型减少了由于前置施工任务的不可靠而导致后置施工任务的等待和闲置以及大量在制品存在的浪费。针对资源配置对于工作流闲置时间和生产力的影响,本文将启发式遗传算法与循环网络仿真技术相结合,提出工作流的资源配置第一阶段遗传算法(HGA-CYCLONE);在第一阶段遗传算法的基础上,提出工作流的滞后缓冲遗传算法(第二阶段遗传算法),对工作流的滞后缓冲值进行优化,以进一步降低工作流的闲置率。施工活动的空间冲突不仅会阻碍工作流的连续流动而且会造成生产力损失。针对目前在工程项目管理中,对施工活动的空间冲突关注较少的情况,本文提出基于4D-CAD的工作流可视化模型。与传统的基于转换模型理论的4D-CAD技术不同,基于4D-CAD的工作流可视化模型采用流动模型理论,应用位置分解结构的方法。根据前述的研究,本文构建了工作流集成管理方法,工作流集成管理方法由以下三个模块组成:仿真模块、优化模块、可视化模块。模块之间的数据交换和共享采用可扩展标记语言(eXtensible Markup Language, XML)实现。综合应用表明,本文提出的工作流集成管理方法解决了不确定工期条件下工作流连续性仿真所需要解决的问题,有效地减少了工作流流动过程中的浪费,实现了建设项目工作流的精益管理。更多还原

【Abstract】 In the worldwide range, the whole management level of construction project is not very high. There exist some questions, such as low productivity, waste and high cost of building. To explore the reason for those questions, absence of theory foundation makes share of impeding development of construction management. Lean construction has been proposed for the solving of such absence. At present, lean construction has been the focus of research in developed countries. However, study on lean construction is just beginning in our country. Relative theory and method of lean construction are faultiness. Exploring and introducing advanced lean contruction thinking which will enhance the productivity of construction, decrease cost and reduce waste effects the survival and development of our country’s construction corporations greatly.Based on lean construction, this dissertation takes work flow and work folw continuity to be research object and make core studies which focus on how to ensure work flow continuity under variability of task duration and how to decrease the waste during the flow process of work flows. Integration CYCLic operation network simulation technology, genetic algorithm, 4D-CAD technology, line of balance, theory of constraints and XMl, this dissertation establishs integrated approach to managing work flow and realizes work flow lean management for construction projects. The main contents and conclusions are summarized as follow:From flow management perspective of lean construction, the concepts of work flow and work flow continuity are defined. Work flow defines as different trades flow through locatins in time and space dimensions in ordet to finish construction tasks and achieve clients’s requirements. The cocept of work flow contains the location flow and assemble flow. Also, the no value-adding activities during the process of flows are summarized.For the variability of construction process, describing the duration of construction task with single number is not reasonable and could not reflect the status of contruction realistically. Accordingly, this dissetation proposed work flow simulation model under uncertainty, which is founded on cyclone. Proposed model which uses object orientation simulation and hierarchical modeling introduces lag buffer node in order to make the early start time of work flow delay to specified value of lag buffer. Validation shows proposed work flow simulation model decrease direct cost and idle time of work flow effectively and enhance continuity of work flow. Consequently, proposed work flow simulation model makes the trade-off optimization of project duration-cost-continuity. At the same time, the proposed simulation model reduces two types of wastes: namely, the successive tasks have to be idle and wait for the uncertainty of predecessor’s tasks; much quantities of work in progress.Considering the effect of resource allocation on work flow idle time and productivity, this dissertation combines heuristic genetic algorithm with cyclone simulation model and proposes HGA-CYCLONE method for work flow resource allocation optimization (the first level genetic algorithm); based on the first level genetic algorithm, this dissertation proposes work flow lag buffer’s genetic algorithm (the second level genetic algorithm) to optimize value of lag buffer in order to further decrease work flow idle rate.The time-space conflicts impede the continuous flows of work and decrease the productivity. Little attention has been put on space conflict in nowadays project management practice. So this dissertation proposes work flow visualization model based on 4D-CAD technology. Different form traditianal 4D-CAD technology which is founded on transformation model, proposed work flow orientation 4D-CAD technology applies flow model and utilizes concept of location breakdown structure. Based on aforementioned studies, this dissetation constructs integrated approach to managing work flow. The constructed integrated approach consists of three modules: simulation model; optimization model; visualization model. The data exchange realizes through eXtensible Markup Language.Integration application shows that integrated approach to managing work flow resolves requirements that need to be addressed when using simulation tools to model work flow continuity under uncertainty of work flow duration and reduces work flow waste during the process of flows effectively, consequently realizes work flow lean management for construction projects.更多还原