以分配浮時擁有權為基礎之遲延分析方法

Delay Analysis Method of Allocating Floats on Ownership Base

蔡奇成(Chi-Chen Tsai)

指導教授 ： 王明德

共同指導教授 ： 張陸滿

國立臺灣大學/工學院/土木工程學研究所/博士(2014年)

https://doi.org/10.6342/NTU.2014.01238

摘要

在工程契約的履約階段，最常見的爭議即是遲延的爭議，當遲延爭議發生時，必須利用遲延分析方法以分擔遲延責任歸屬。而浮時擁有權乃公認遲延分析之重要議題，然卻常在遲延分析中之簡單假設下而未做分析。再者，目前實務界多認為浮時擁有權係屬專案，致使履約當事人使用浮時不須付出任何代價，履約當事人即使沒必要也可以使用浮時，此時將會有可能影響浮時於時程管理之功能，且後使用浮時者常需負擔較大之遲延風險。
為解決這些問題，過去許多學者紛紛提出解決之道。本研究旨在建構一個新的，以分配浮時擁有權為基礎之遲延分析方法，以做為事前在契約條款內約定浮時擁有權之參考與在事後做為遲延爭議分析及處理之機制。本研究以要徑風險性與成本效率性二大觀念為基礎，以補充過去方法之不足。在要徑風險性上，係以蒙地卡羅模擬分析，得出各作業相對風險之要徑指數，接續以要徑指數做為分配路徑浮時與遲延責任歸屬之依據。在成本效率性上，係以總成本最低做為浮時分配之依據，以得專案總成本最低之結果。
本研究結果發現，在浮時之分配上，過去方法多以路徑上各工作項目間作業時間之多寡，做為分配浮時之依據，即作業時間愈多，可分配之浮時就愈多。本研究以要徑指數做為分配之依據，換言之，遲延風險越高的作業被分配較多之浮時。另外，過去方法多將浮時平均分配給相關使用者，本研究發現浮時若以平均分配，總成本不一定為最低。最後，在遲延責任歸屬上，過去的方法，未考慮到非要徑上遲延與要徑上遲延責任歸屬之權重問題。本研究所提出之方法，正本溯源回歸到要徑之重要性，可避免當事人即使在要徑上遲延，因該當事人尚擁有非要徑之分配浮時，而不須負擔任何遲延責任的問題。
本研究所建立之專案總成本為基礎之要徑指數遲延分析方法，係為一重新考量浮時之分配與遲延責任歸屬之系統化方法，可用來在契約條款內事前約定浮時使用權利之歸屬之參考與在事後做為遲延爭議分析及處理之機制，亦適用於對浮時擁有權議題認知差異過大之履約當事人。

關鍵字

遲延 ； 浮時 ； 浮時擁有權 ； 成本 ； 要徑指數

並列摘要

Delay dispute is one of the most common disputes during the execution of constructed project. When a delay dispute occurs, delay analysis must be adopted to attribute responsibility for the delay. Float ownership is recognized as the critical issue in delay analysis; however, float ownership is often not analyzed using the basic assumptions of delay analysis. Furthermore, most of practitioners believed that the float should belong to the project, and therefore parties executing the contract of the project do not need to pay any consideration when using the float, even, it is not necessary. This may affect the functions of schedule management. Meanwhile, the user of later float might commonly bear a larger delay risk.
To solve these problems, many scholars had proposed various methods. The primary objective of this study is to construct a new delay analysis method based on the assignment of float ownership. This new method can be used to be a reference to establish contract provisions of float ownership before signing a contract and to serve as a mechanism for resolving and analyzing delay disputes during contract performance. The concepts of criticality of potential risk and cost efficiency are employed as a foundation to address the insufficiency of methods proposed in the past. From the prospect of criticality of the associated risk, this study allocated float and delay responsibility by using criticality index of each activity which was derived from Monte Carlo simulation. From the prospect of cost efficiency, the cost efficiency is measured by the least impact on total cost due to the delay. In other words, the project will result in minimum cost.
The results of this study indicate that, in terms of float allocation, in the most of past methods, the activity time of each activity is taken as the basis for allocating float. That is, the longer the activity time is, the larger the float should be allocated to that activity. The method utilized in this study uses critical indices as the basis of float allocation. In other words a larger float should be allocated to activities with higher risk due to delayed. This study found that float allocation may not be efficiently optimized when that float is equally shared between users. Moreover, when analyzing the attribution of delay responsibility, past methods did not consider certain problems associated with weight of severity, namely responsibility assignment on those of critical and non-critical delay. This method weight the criticality due to impact of the delay. Thus, it avoids the situation where a delay occurs on the critical path but the liability is not duly assigned because the party delayed the critical path may have extra floats that are pre-allocated on the non-critical path and are used to decline the liability.
The proposed criticality index delay analysis method is based on total project cost impacted by the delay. This method is a systematic approach that considers float allocation and delay responsibility attribution. This method can be used as a reference to establish float ownership attribution before signing a contract and to serve as a mechanism for resolving and analyzing delay disputes and responsibility during contract performance. In addition, this method is suitable for situations where the contractual parties have a large cognitive gap regarding float ownership.

並列關鍵字

delay ； float ； float ownership ； cost ； criticality index

參考文獻

行政院公共工程委員會 (2001)。各機關辦理公有建築物作業手冊。臺北市：行政院公共工程委員會。

林曉瑩與黃麗蓉 (2005)。論業主與承商之共同遲延(上)。營建知訊，268，64-67。

Ahuja, H., & Nandakumar, V. (1985). Simulation model to forecast project completion time. Journal of Construction Engineering and Management, 111(4), 325-342.

Al-Gahtani, K. S. (2009). Float allocation using the total risk approach. Journal of Construction Engineering and Management, 135(2), 88-95.

Al-Saggaf, H. A. (1998). The five commandments of construction project delay analysis. Cost Engineering, 40(4), 37-41.