scholarly journals Importance and Ranking Evaluation of Cost Overrun Factors for Oil Transmission Pipeline Projects

Author(s):  
Pooneh Saidi
2020 ◽  
Vol 38 (7A) ◽  
pp. 1069-1076
Author(s):  
Layth T. Ali ◽  
Raid S. Abid Ali ◽  
Zeyad S. M. Khaled

Cost overrun in construction projects is a common phenomenon in Iraq. This might occur due to diversity of factors. This study aims to identify the factors influencing construction projects cost that are potentially controllable by main contractors. A field study through a questionnaire survey was directed to a sample of related Iraqi professional engineers from general contracting companies at both public and private sectors. Their opinions on the impact and frequency of each factor were investigated. The questionnaire offered (59) factors classified in (8) categories namely; legislations, financial and economic, design, contractual, site management, material, labor and equipment. The factors were ranked according to the highest Relative Importance Index (RII). The study revealed (10) major factors that are potentially controllable by main contractors namely; labor productivity, sub-contractors and suppliers performance, equipment productivity, site organization and distribution of equipment, experience and training of project managers, scheduling and control techniques, planning for materials supply, planning for equipment supply, materials delivery and planning for skilled labor recruitment. Recommendations to aid contractors and owners in early identification of these factors are also included in this study.


Author(s):  
Ahmed Salem Ahmed Marey Alhammadi ◽  
◽  
Aftab Hameed Memon ◽  

UAE construction industry frequently faces poor cost performance which commonly known as cost overrun problem. This problem is resulted from several factors and it is important to identify these cost overrun factors in order to avoid and minimize it. Hence, this paper focused on determined the relevancy of factors affecting cost performance in construction projects of UAE. Through a review of past research works conducted globally, 27 factors of cost overrun were listed and used for developing a structured questionnaire. A survey was conducted with 33 practitioners from client, consultant and contractors organizations involved in handling construction projects in UAE. The respondents were requested to state their perception regarding the relevancy of each of the factors that was perceived in context with cost overrun issue using 5-points Likert scale. The responses were analysed using average index method and the results found that all the 27 factors are relevant with construction industry of UAE in causing cost overrun. These factors can be used for further investigation to uncover critical problems of cost overrun.


Author(s):  
Yin Wang ◽  
Zhirong Jerry Zhao

Given the current momentum for public–private partnerships (PPPs), it is critical to review the experiences of PPP highway projects to see whether they succeed in serving public benefits. This article applies a goal-centered approach to evaluate the effectiveness of nine PPP highway projects in the Commonwealth of Virginia, U.S.A., that were implemented and opened to traffic between 1990 and 2016. Virginia has used highway PPPs more for financing or risk reduction than for efficiency gains. The authors examine four elements of contract agreements—PPP type, private partner selection, financial arrangements, and risk allocation—in these Virginian projects, and find that these arrangements have been effective in accessing innovative finance and preventing cost overrun, while the evidence is limited regarding shifting revenue risk or achieving efficiency gains.


Author(s):  
Trevor Place ◽  
Greg Sasaki ◽  
Colin Cathrea ◽  
Michael Holm

Strength and leak testing (AKA ‘hydrotesting’, and ‘pressure testing’) of pipeline projects remains a primary method of providing quality assurance on new pipeline construction, and for validating structural integrity of the as-built pipeline [1][2][3]. A myriad of regulations surround these activities to ensure soundness of the pipeline, security of the environment during and after the pressure testing operation, as well as personnel safety during these activities. CAN/CSA Z662-11 now includes important clauses to ensure that the pipeline designer/builder/operator consider the potential corrosive impacts of the pressure test media [4]. This paper briefly discusses some of the standard approaches used in the pipeline industry to address internal corrosion caused by pressure test mediums — which often vary according to the scope of the pipeline project (small versus large diameter, short versus very long pipelines) — as well as the rationale behind these different approaches. Case studies are presented to highlight the importance of considering pressure test medium corrosiveness. A practical strategy addressing the needs of long-distance transmission pipeline operators, involving a post-hydrotest inhibitor rinse, is presented.


Author(s):  
Shozo Hatanaka ◽  
Masahiko Tange ◽  
Morio Sumiyama

It is necessary to avoid spreading damage to the pipe when it is struck by construction equipment. It is difficult to install indirect methods (e.g. fiber optic sensors) for detection of construction equipment in heavy traffic areas. Therefore, remote monitoring systems, which can detect contact between such equipment and the steel of polyethylene-lined pipe, were developed and installed on a gas transmission pipeline (φ 600 mm, Length 9.4 km). Detection uses the change in pipe-to-earth resistance which is derived from inner pipe current and pipe to soil potential when contact occurs. Old and new data of pipe-to-earth resistance are continuously compared. If equipment contacts the steel pipe, pipe-to-earth resistance will drop below 100 Ω. The detection systems include maximal length sequence signal (pseudo-random signal) processing. This signal processing is superior for noise reduction. These systems also have remote monitoring of the cathodic protection condition (pipe to soil potential, current of coupons (probes), and transformer rectifier output voltage and current). From the office, pipeline lining and cathodic protection conditions are monitored at all times.


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