标题: 机电工程数量计算方法之案例探讨
Case Studies of Quantity Takeoffs in Mechanical/Electrical/Plumbing Construction Projects
作者: 林耀祥
王维志
Lin, Yao-Shiang
Wang, Wei-Chih
工学院工程技术与管理学程
关键字: 机电工程;机电设备;机电管线;数量计算;机电计算方法;Mechanical/Electrical/Plumbing (MEP) Construction;MEP equipment,;Cables/Pipes,;Quantity Takeoffs
公开日期: 2015
摘要: 工程成本估算的基本概念为单价乘以数量,单价与数量这两项发生估算错误时,对成本都会造成影响,其中数量计算发生错误之情形,极为频繁。目前数量计算多着重于土建部分,对机电工程之数量计算较为忽略,然而机电工程约占总工程造价之15%~30%,若有估算错误,影响亦甚钜。为利厘清与归纳机电工程数量计算之方法,本研究包括三个部份:(1)机电工程之分类、(2)机电工程数量计算之原则与流程,以及(3)案例分析。
在机电工程分类方面,本研究依照机电工程不同的三种属性,分别分类探讨。第一,若依系统特性,可分为为机械系统及电气系统等两类,再依照系统功能,可向下细分各种子系统。第二,若依管线之传输物质,机电工程可区分为电能系统、液体系统及复合系统等3种类型,再依照系统功能向下细分各种子系统。第三,若依计算单位,可分类为单位计算及比例计算等2类。在此部分之探讨,本研究亦分析影响数量计算的重要因素(称为计算关键)。
在机电工程数量计算之原则与流程方面,本研究分析机电工程在实务上采用之数量计算方式,并依据传输物质分类,探讨各类型系统之组成设备、管线。再就此进行实务经验之汇整,针对不同机电工程之系统,分别探讨各类别所需计算之项目及其计算单位,此部分可归纳出机电工程数量计算项目,可分为设备、管线与风管三类,计算单位分别为点数、长度与面积。
在案例分析方面,透过本研究提出的机电工程数量计算方式,进行案例分析。分析结果显示,除本研究所提之计算原则与流程,应属可行,所整理之计算关键应可协助工程人员理解机电工程之数量计算。
Estimating construction costs is related to the unit cost and quantity for each cost item. That is, accurately conducting quantity takeoffs (QTO) is crucial to generate acceptable cost estimates. Current practice pays much attention to the QTO of Civil/Structure/ architectural (CSA) construction part of a construction project. However, the Mechanical/Electrical/Plumbing (MEP) part could be approximately 15% to 30% of the total costs for of a construction project. To improve better understanding of the quantity takeoffs method for MEP construction, the study investigates three aspects, including the classification methods of MEP, the MEP takeoffs process and principles, and case study.
Regarding the classification methods of MEP, three conclusions are derived. First, based on system characteristics, the MEP can be classified as mechanical systems and electrical systems. And they can be further sub-categorized according to system functions. Second, base on piping line transmission substance, the MEP can be divided into electrical energy systems, liquid systems, and composite systems. Again, they can be further sub-categorized according to system functions. Third, “units” are “ratios” are the two methods to conduct QTO.
Regarding the MEP takeoffs process and principles, this study analyzes transmission substance categories and discusses the component of equipment and pipeline. This work integrates practical experience to discuss every category takeoffs method. Additionally, the cost items that can be categorized for QTO for MEP are equipment, piping line and duct. The quantity takeoffs units are identified to be point, length, and area.
Regarding the case study, this study applies the MEP takeoffs process and principles to a case project. The results show that the proposed process and principles are feasible. Finally, the factors affecting QTO that are identified in this study should help inexperienced engineers to understand the takeoffs for MEP projects.
URI: http://etd.lib.nctu.edu.tw/cdrfb3/record/nctu/#GT070161220
http://hdl.handle.net/11536/140528
显示于类别:Thesis