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Factors Affecting the Accuracy of Pre-Tender Cost Estimates in the Gaza Strip

01 Jan 2013-Vol. 18, Iss: 1, pp 73-94
TL;DR: In this article, a survey questionnaire was conducted to elicit professionals' views on and experiences with factors affecting the accuracy of pre-tender cost estimates; a total of 70 organizations responded to the survey.
Abstract: Pre-tender cost estimates of construction projects require extensive knowledge and expertise. The aim of this paper is to identify, evaluate and rank essential factors affecting the accuracy of pre-tender cost estimating from the perspective of clients and consultants. A survey questionnaire was conducted to elicit professionals' views on and experiences with factors affecting the accuracy of pre-tender cost estimates; a total of 70 organisations (i.e., 46 clients and 24 consultants operating in the Gaza Strip, Palestine) responded to the survey. The results of analysing a total of 64 factors considered in the questionnaire reveal that the top five factors affecting the accuracy of pre-tender cost estimating are (1) materials (prices/availability/supply/quality/imports), (2) closure and blockade of borders, (3) project team's experience in the construction type, (4) the experience and skill level of the consultant and (5) clear and detailed drawings and specifications. Kendall's coefficient of concordance was used as a measure of agreement between the two groups of respondents (i.e., clients and consultants) who ranked various factors and it appears that they are generally in agreement. Both clients and consultant groups should focus on the main factors identified in this study to develop effective strategies for accurate cost estimating, which would ultimately lead to successful projects.

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Citations
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Journal ArticleDOI
TL;DR: In this paper, the authors identify the critical factors that affect accuracy of cost estimation and evaluate the degree to which these factors are important from contractors' and consultants' viewpoints from an open-ended interview with 11 project managers.
Abstract: Purpose Cost estimating process is an important element within the project life cycle. Comprehensive information, expanded knowledge, considerable expertise, and continuous improvement are needed to obtain accurate cost estimation. The main objectives of this study are to identify the critical factors that affect accuracy of cost estimation and evaluate the degree to which these factors are important from contractors’ and consultants’ viewpoints. Design/methodology/approach Qualitative, and quantitative research approaches were adopted in collecting and analyzing the data, and testing the hypotheses. Based on literature review, a questionnaire was prepared and then was modified according to the results of face-to-face open-ended interviews conducted with 11 project managers. The final version of the questionnaire was distributed to a random sample of 265 respondents. For analyzing the collected data Kendall’s and Mann Whitney tests were conducted Findings The analysis revealed that there is a strong agree...

41 citations

Journal ArticleDOI
TL;DR: In this article, the most important factors influencing post-disaster reconstruction project management (PDRPM) for housing in the Gaza Strip are identified, rank, and discuss the most significant factors influencing PDRPM for housing provision in theGaza Strip are related to issues associated with financial resources.
Abstract: In the Occupied Palestinian Territories, the Gaza Strip has suffered regular cycles of reconstruction due to systematic destruction during Israeli military operations, as in 2006, 2008–2009, 2012, and 2014. In this context of ongoing conflict this article aims to identify, rank, and discuss the most important factors influencing post-disaster reconstruction project management (PDRPM) for housing in the Gaza Strip. A set of key factors that influence PDRPM were assembled as a result of a global literature review. A questionnaire survey was conducted, and the obtained data were analyzed using a relative importance index for each PDRPM factor. Findings are presented in six groups: housing approaches, organizational behavior, project funding, supply chain and logistics, communication and coordination, and PDRPM context. Findings indicate that the most significant factors that influence PDRPM for housing provision in the Gaza Strip are related to issues associated with financial resources. It is critical that sufficient funding should be available in order to allow organizations to undertake housing projects in an effective and efficient way. Joint efforts are required from international donors and local organizations in order to effectively manage financial resources with the ultimate goal of improving PDRPM for housing provision.

23 citations


Cites background or methods from "Factors Affecting the Accuracy of P..."

  • ...The RII ranges from 0 to 1 (Le and Tam 2007; Enshassi et al. 2013)....

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  • ...The blockade and closure also limit the amount, type, and quality of materials allowed through borders, with negative economic impacts, including price escalation and monopolies on the available construction materials by a few suppliers (Enshassi et al. 2011, 2013)....

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  • ...The survey was administered in September 2014 as a consolidated research approach used for the assessment of factors that influence the construction sector in the Gaza Strip (Enshassi et al. 2007, 2009, 2011, 2013, 2015)....

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  • ...According to previous research in the Gaza Strip (Enshassi et al. 2009, 2011, 2013), issues related to material procurement and availability are driven primarily by the blockade and border closure....

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Journal ArticleDOI
TL;DR: In this article, the authors investigated the application of lean construction techniques in reducing accidents in construction projects and found that LC techniques are poorly implemented in construction project in the Gaza Strip, while the highest three LC techniques applied to reduce the causes of accidents that were applicable were cleaning the workplace and removing materials and machines that are not required; conducting accident investigation and root cause analysis programs; and using safety signs and labels on site.
Abstract: This paper aims to investigate the application of lean construction (LC) techniques in reducing accidents in construction projects.,A quantitative approach was used to collect the required data using a questionnaire survey and descriptive analysis was used to analyse the collected data. The LC techniques that were investigated in this paper are related to the tools of the last planner system (LPS), increased visualisation (IV), 5S, error-proofing, daily huddle meetings (DHMs), first-run studies (FRS), continuous improvement (Kaizen) and accident investigation (5Whys).,The overall results indicated that LC techniques are poorly implemented in construction projects in the Gaza Strip. The top three LC tools used to reduce the causes of accidents in the Gaza construction projects were 5Whys, 5S and LPS, while the highest three LC techniques applied to reduce the causes of accidents that were applicable were cleaning the workplace and removing materials and machines that are not required; conducting accident investigation and root cause analysis programmes; and using safety signs and labels on site.,There is a lack of information and published studies regarding the links between LC and safety, especially in the Middle East. This paper is limited to the perceptions and geographical boundaries; therefore, it cannot be generalised. However, it could form the basis for useful comparison in the future. Triangulation research method could also be used in future research to minimise the bias and validate the conclusions.,The findings of this paper will stress professionals and construction companies in Gaza to reconsider their behaviour towards using LC techniques. The findings of this paper will aid them to shift their attention and resources towards including LC techniques in their plans to reduce the causes of accidents on construction sites.,The findings of this paper will encourage professionals and construction companies in Gaza to reconsider their behaviour towards using LC techniques. The findings will also aid them to shift their attention and resources towards including LC techniques in their plans to reduce and/or avoid the causes of accidents on construction.,Because of the lack of published works that are specific to the Middle East, the authors believe that the originality lies in the paper’s serious attempt to explore the application level of the LC concept to safety in this part of the world. This paper contributes to a better understanding of the applicability of LC techniques in terms of accidents reduction. Findings from this paper provide a clear picture of the current status of using LC techniques to reduce accidents in the Gazan construction projects which drive them to investigate the main barriers and try to overcome them.

17 citations

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a model based on a prevention, rather than detection, approach to handling unbalanced bidding, which balances all the bids submitted for a project and thereby neutralizes the impact of manipulating bid prices to obtain undeserved payments from owners.
Abstract: Unbalanced bidding is a common practice associated with both unit price and lump sum contracts. This practice is not usually in the owner’s best interests and is used in different forms by contractors for various reasons. Bid evaluation practices try to identify unbalanced bids and may reject the lowest bid if it is perceived to be unbalanced. Previous research on this topic focused on either helping contractors unbalance their bids or detecting imbalance in bids in order to reject them. This paper proposes a model based on a prevention, rather than detection, approach to handling unbalanced bidding. The proposed model balances all the bids submitted for a project and thereby neutralizes the impact of manipulating bid prices to obtain undeserved payments from owners. This approach protects the interests of the owners while maintaining the essence of competitive bidding by awarding the project to the bidder who submitted the lowest bid in a fair competitive process. Two examples, representing the b...

17 citations


Cites result from "Factors Affecting the Accuracy of P..."

  • ...Existing models are only approximate (Arditi and Chotibhongs 2009) and depend mainly on the engineer’s estimate, which is not as accurate as the contractor’s estimate (Enshassi et al. 2013; Grilley 2009; Arditi and Chotibhongs 2009)....

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References
More filters
Book
01 Jan 1956
TL;DR: This is the revision of the classic text in the field, adding two new chapters and thoroughly updating all others as discussed by the authors, and the original structure is retained, and the book continues to serve as a combined text/reference.
Abstract: This is the revision of the classic text in the field, adding two new chapters and thoroughly updating all others. The original structure is retained, and the book continues to serve as a combined text/reference.

35,552 citations

Posted Content
TL;DR: In this paper, the authors present a comparative study of actual and estimated costs in transportation infrastructure development, with a sample of 66 transportation projects, which approaches a large-sample study and takes a step toward valid statistical analysis.
Abstract: Es gibt nur wenige vergleichende Studien uber reale und geschatzte Kosten derEntwicklung von Verkehrsinfrastruktur. Wo solche Studien vorliegen, beziehen siesich auf Einzelfalle, oder die Stichprobe ist zu klein, um systematische statistische Analysen zuzulassen (Bruzelius et al. 1998, Fouracre et al. 1990, Hall 1980, Nijkamp/Ubbels 1999, Pickrell 1990, Skamris/Flyvbjerg 1997, Szyliowicz/Goetz 1995, Walmsley/Pickett 1992). Nach unserem Kenntnisstand ist bislang nur eine Studie veroffentlicht, die auf der Basis von 66 Transportprojekten einen breit angelegtenZugang wahlt und erste Schritte auf dem Weg zu einer stichhaltigen statistischen Analyse unternimmt (Merewitz 1973a, 1973b).Existing comparative studies of actual and estimated costs in transportation infrastructure development are few. Where such studies exist, they are typically single-case studies or they cover a sample of projects too small to allow systematic, statistical analyses (Bruzelius et al., 1998; Fouracre et al., 1990; Hall, 1980; Nijkamp & Ubbels, 1999; Pickrell, 1990; Skamris & Flyvbjerg, 1997; Szyliowicz & Goetz, 1995; Walmsley & Pickett, 1992). To our knowledge, only one study exists that, with a sample of 66 transportation projects, approaches a large-sample study and takes a first step toward valid statistical analysis (Merewitz, 1973a, 1973b).The English version of this article can be found at: http://www.ssrn.com/abstract=2278415Den Svenska versionen av denna artikel finns pa: http://papers.ssrn.com/abstract=2278382La versione italiana di questo documento e disponibile al seguente link: http://www.ssrn.com/abstract=2278294

1,237 citations

Journal ArticleDOI
TL;DR: In this paper, the authors present results from the first statistically significant study of cost escalation in transportation infrastructure projects and find that the cost estimates used to decide whether such projects should be built are highly and systematically misleading.
Abstract: This article presents results from the first statistically significant study of cost escalation in transportation infrastructure projects. Based on a sample of 258 transportation infrastructure projects worth US$90 billion and representing different project types, geographical regions, and historical periods, it is found with overwhelming statistical significance that the cost estimates used to decide whether such projects should be built are highly and systematically misleading. Underestimation cannot be explained by error and is best explained by strategic misrepresentation, that is, lying. The policy implications are clear: legislators, administrators, investors, media representatives, and members of the public who value honest numbers should not trust cost estimates and cost-benefit analyses produced by project promoters and their analysts.

1,123 citations

Book
15 Jan 1997
TL;DR: In this article, the authors present a guide for students involved in research in construction management, building and quantity surveying, covering topics selection, research planning, data collection and methodology, as well as structuring and writing the dissertation.
Abstract: User-friendly, easy to dip into guide for all Built Environment students Takes the reader from the stage of choosing a topic to writing a well-structured dissertation Best case practice illustrated with numerous examples, case studies and references Dissertation Research and Writing for Construction Students covers topic selection, research planning, data collection and methodology, as well as structuring and writing the dissertation - in fact, everything needed for a successful write-up A new section advising students on the use of the SPSS software 'Statistical Package for Social Sciences' will help readers make the best use of this tool New examples and references ensure that this new edition of the bestselling construction dissertation guide is right up to speed with current practice This is the ideal resource for students involved in research in Construction Management, Building and Quantity Surveying

783 citations


"Factors Affecting the Accuracy of P..." refers methods or result in this paper

  • ...These results are in agreement with the findings of Trost and Oberlender (2003) and Babalola and Aladegbaiye (2006) who have shown that the client experience level plays a significant role in cost estimate accuracy....

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  • ...A pilot study, as suggested by Naoum (1998), provides a trial run for the questionnaire and involves testing the wording of questions, identifying ambiguous questions, testing the techniques used to collect data and measuring the effectiveness of standard invitations to respondents....

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Journal ArticleDOI
TL;DR: In this paper, the main factors relevant to cost estimating practice are complexity of the project, scale and scope of the construction, market conditions, method of construction, site constraints, client's financial position, buildability and location of a project.
Abstract: Although extensive research has been undertaken on factors influencing the decision to tender and mark-up and tender price determination for construction projects, very little of this research contains information appropriate to the factors involved in costing construction projects. The object of this study was to gain an understanding of the factors influencing contractors' cost estimating practice. This was achieved through a comparative study of eighty-four UK contractors classified into four categories, namely, very small, small, medium and large firms. The initial analysis of the 24 factors considered in the study shows that the main factors relevant to cost estimating practice are complexity of the project, scale and scope of construction, market conditions, method of construction, site constraints, client's financial position, buildability and location of the project. Analysis of variance, which tests the null hypothesis that the opinions of the four categories of companies are not significantly di...

559 citations


"Factors Affecting the Accuracy of P..." refers background or methods or result in this paper

  • ...These results are still consistent with the findings of previous studies undertaken by Akintoye (2000), Elhag, Boussabaine and Ballal (2005) and Odusami and Onukwube (2008)....

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  • ...The results are in agreement with previous studies, asserting that the accuracy of a cost estimate is highly dependent on the level of detail and adequate project scope because it is a definition of the client's requirements for space, function and quality of the proposed project (Akintoye, 2000; Trost and Oberlender, 2003; Babalola and Aladegbaiye, 2006; Dysert, 2006; Liu and Zhu, 2007; Odusami and Onukwube, 2008). Client's method of payment was ranked last by both clients and consultants for this group with an RII of 0.666 and was ranked 59th in the overall ranking. Both client and consultant groups agreed that this factor does not play a significant role in pre-tender cost estimate accuracy This result somehow contradicts the findings of Al-Khaldi (1990), in Saudi Arabia, who concluded that client's method of payment has a very strong effect on the accuracy of the estimated cost....

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  • ...…the level of detail and adequate project scope because it is a definition of the client's requirements for space, function and quality of the proposed project (Akintoye, 2000; Trost and Oberlender, 2003; Babalola and Aladegbaiye, 2006; Dysert, 2006; Liu and Zhu, 2007; Odusami and Onukwube, 2008)....

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  • ...A total of 85 factors that were identified and reported in 12 previous studies (Al-Khaldi, 1990; Al-Thunaian, 1996; Akintoye, 2000; Madi, 2003; Trost and Oberlender, 2003; Elhag et al., 2005; Shash and Ibrahim, 2005; Babalola and 76/PENERBIT UNIVERSITI SAINS MALAYSIA Aladegbaiye, 2006; Dysert,…...

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  • ...These results match findings by Odusami and Onukwube (2008) and Akintoye (2000)....

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