重大工程项目总工期延误中的奇异现象研究

发布时间：2018-09-10 06:59

【摘要】：工程项目中,各部门在时间方面日益激烈的竞争已成为当前的趋势。时间在上世纪八十年代就被认为是一种竞争优势资源,并且项目的时间性能现已是吸引项目管理者致力于改进的一个主要目标。重大工程项目的建设就其产出效果而言,要么对国民经济的发展起积极的推动作用,反之则对国民经济发展起消极作用,影响经济秩序和社会发展,所以历来受到国家和社会的高度重视和广泛关注。本文受重大项目运用模拟仿真方法寻找隐藏工作思路的启发,通过研究网络计划的路长的悖论,确定了工序之间存在的重叠、等待等各类约束能够产生隐性工序。本文通过研究各类约束的特性给出了寻找隐性工序的方法,证明了隐性工序是一类特殊的约束工序,它不消耗任何人、财、物等资源,但是它又伴随着对应的实工序所共生,其大小,随着对应的实工序的大小变化而变化。带有隐性工序的实工序与普通的实工序相比,在性质上也发生了巨大的变化,例如无隐性工序存在的实工序,其机动时间只能越用越少,绝对不可能越用越多；但是有隐性工序存在的实工序,其机动时间可能越用越多。为了更好地研究这些现象,我们定义了一种新的网络—隐性网络,定义了时间参数、证明了隐性网络中的路长和时间网络中的时间参数(特别是机动时间)的关联规律,且一进步论证了隐性网络具有允许负回路的存在、工序的最长路线不唯一,带有零回路和不带有零回路的最大路长值不同三个方面的特别性质,还论述了隐性网络回路的特性。并在隐性网络中研究了关键工序的工期变化对总工期的影响。分析了正关键工序、反关键工序和点关键工序的动态特性,给出了变化范围。从这些特性可以看出,对于关键工序的使用不当,不但不能够起到优化工期的作用反而会导致总工期推迟。在研究关键工序的特性后,我们自然地想到了非关键工序。在讨论非关键工序的时候,我们发现了非关键工序的四种奇异现象,根据理论上和逻辑上的推理,得出了在隐性网络中,非关键工序的总时差并不总是一个值,而是根据其使用方式的不同,具有三个值。因此我们定义了三种总时差,分别是移动总时差、延长总时差和缩短总时差,并且给出了这三种总时差的计算方法及其正确性证明。分析了工序机动时间使用可能会导致总工期推迟的现象。总时差的多值性这一概念是首次在本文提出,该概念的提出打破了传统的总时差只有一个唯一值的固化思维,为隐性网络的优化理论打下了坚实的基础。
[Abstract]:In the engineering project, each department in the time aspect day by day intense competition has become the present tendency. Time has been regarded as a competitive advantage resource in the 1980s, and the time performance of the project has been a main goal to attract project managers to improve. In terms of its output effect, the construction of major engineering projects will either play a positive role in promoting the development of the national economy, otherwise, it will play a negative role in the development of the national economy and affect the economic order and social development. Therefore, it has always been highly valued and widely concerned by the state and society. This paper is inspired by the application of simulation method to find hidden working ideas. By studying the paradox of network plan length, this paper determines the overlap between processes, and waits for all kinds of constraints to produce hidden processes. In this paper, by studying the characteristics of various kinds of constraints, we give a method to find the implicit process, and prove that the implicit process is a special kind of constrained process, which does not consume any resources, such as money, material, etc., but it is accompanied by the symbiosis of corresponding real processes. Its size varies with the size of the corresponding real process. Compared with ordinary real processes, the real processes with recessive processes also have a great change in nature. For example, if there is no hidden process, the mobile time can only be used less and less, so it is absolutely impossible to use more and more. However, the actual processes with hidden processes may be used more and more. In order to study these phenomena better, we define a new kind of network-recessive network, define the time parameter, prove the correlation law of the path length in the recessive network and the time parameter (especially the maneuvering time) in the time network. One step forward proves that the hidden network has three special properties: the existence of the allowable negative loop, the non-unique longest route of the working procedure, and the difference of the maximum length between the zero loop and the non-zero loop. The characteristics of the hidden network loop are also discussed. The influence of the change of the key process duration on the total duration is studied in the recessive network. The dynamic characteristics of positive, inverse and point key processes are analyzed, and the range of variation is given. From these characteristics, it can be seen that the improper use of the key processes can not only not play the role of optimizing the duration, but also lead to the delay of the total duration. After studying the characteristics of key processes, we naturally think of non-critical processes. In the discussion of non-critical processes, we find four strange phenomena in non-critical processes. According to theoretical and logical reasoning, it is concluded that the total time difference of non-critical processes is not always a value in a recessive network. Instead, there are three values depending on how they are used. Therefore, we define three kinds of total time difference, that is, moving total time difference, extending total time difference and shortening total time difference, and give the calculation method and its correctness proof of these three kinds of total time difference. This paper analyzes the phenomenon that the use of the working procedure maneuvering time may lead to the delay of the total construction period. The concept of multivalued total time difference is first put forward in this paper. It breaks the traditional fixed thinking that total time difference has only one unique value and lays a solid foundation for the optimization theory of recessive network.
【学位授予单位】：华北电力大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU722;F284

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