The Accuracy of Hybrid Estimating Approaches: A Case Study of an Australian State Road &amp; Traffic Authority

Liu, Li; Wehbe, George; Sisovic, Jonathan

doi:10.1080/0013791x.2010.502962

Cited by 25 publications

(18 citation statements)

References 30 publications

(39 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The determination of an appropriate construction contingency level has been the subject of an on-going debate and a detailed review is outside the scope of this paper (eg, refer to Liu and Zhu, 2007;Liu et al, 2010). Nonetheless, Clark and Lorenzo (1985) have suggested a value of 3% to 5% of the contract value should be used.…”

Section: Quantification Of Overrunsmentioning

confidence: 99%

“…Projects can experience considerable cost overruns and still be delivered on time and vice versa. Whilst cost and time overruns have been the focus of much of the literature, it is worth noting that wider evaluation techniques (eg, whole-life costing and cost-benefit analysis) can be employed to assess whether the additional cost can give rise to larger benefits (value) or life-cycle costs can be reduced by a greater initial investment in capital costs (Kwak et al, 2009;Liu et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

“…The main consequence of optimism bias and strategic misrepresentation in cost estimation is the failure to account fully for the risks and uncertainties in the forecasts, due mainly to the view that "results are determined purely by their own actions and those of their organizations" (Lovallo and Kahnemann, 2003, page 59). As a consequence, this may lead to flawed planning, a breakdown in relationships between the client and contractors, and create implementation problems that contribute to cost and schedule overruns (Liu et al, 2010). However, this may be an oversimplification of what is a complex problem that requires more rigorous analysis.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Understanding the Landscape of Overruns in Transport Infrastructure Projects

Love

Smith

Simpson

et al. 2015

Environ Plann B Plann Des

View full text Add to dashboard Cite

Cost and schedule overruns are endemic features of transport infrastructure projects. Despite the considerable amount of research within the field of transport and planning in the past thirty years, limited progress has been made to improving the performance of projects. We contend that this will continue to be an issue as long as research efforts focus on the ‘outside view’ with emphasis being placed upon strategic misrepresentation and optimism bias. Understanding ‘why’ and ‘how’ projects overrun, particularly from both ‘outside’ and ‘inside’ perspectives, is pivotal to reducing their impact and occurrence. Thus, in conjunction with the transport and planning literature, references to cost-overrun studies undertaken within the field of construction and engineering are examined. Our objective is to provide policy makers, industry, voluntary organizations, and the public at large with an ameliorated understanding about time-overrun and cost-overrun phenomena. Suggestions to mitigate overruns based upon recent process and technological innovations are identified and discussed.

show abstract

Section: Quantification Of Overrunsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Understanding the Landscape of Overruns in Transport Infrastructure Projects

Love

Smith

Simpson

et al. 2015

Environ Plann B Plann Des

View full text Add to dashboard Cite

show abstract

“…Studies report that inaccuracy in cost estimation ranges from 20.4 to 44.7% (Liu et al 2010), and despite decades of efforts to reduce project cost overruns, large infrastructure projects still continue to be plagued by delays and large cost overruns (Liu et al 2010). However, in road and highway projects not only the initial construction costs are important: road management starts from the premise that the road network is an asset which needs to be maintained and improved so as to secure the best performance and value-for-money and the maximum service life (Danielson et al 1998).…”

Section: Introductionmentioning

confidence: 98%

Estimating a Unit Price for Roads Maintenance Activities Using Exponential Robust Regression

Moena

Serpell

2014

Journal of Civil Engineering and Management

View full text Add to dashboard Cite

Good road maintenance schemes allow reducing costs and extending the service life of roads. There are several methods to plan these project maintenances but all of them require input information about maintenance costs, which can be very different depending on the geographical zone and the contracted volume. Nowadays agencies do not have written documentation on the entire process for preparing project estimates, and experience plays an important role in price estimation. In this paper, a structured methodology for estimating a unit price for road maintenance activities is proposed, modeling the exponential decay nature of economies of scale. Using an exponential robust regression procedure, curves are adjusted and parameters generated. Additionally, a cost contingency analysis is performed in order to provide cost ranges associated to specific contracted volumes. The validation of the methodology was carried out through its use in the estimation of real unit prices of historic road maintenance projects in Chile. The procedure may be used by road planners as well ascontractors looking for a more confident approach before participating in a bid. Furthermore, this methodology is not limited to road maintenance only, but also to any other field where economies of scale and exponential fitting are needed.

show abstract

“…Bordat et al 2004;Odeck, 2004;Vidalis and Najafi, 2004;Liu et al, 2010;Canteralli et al, 2012a,b,c;Love et al, 2015a;Odeck et al, 2015;Verweji et al, 2016a;Terrill and Dankes, 2016), the number that have focused on rail projects has been limited (e.g., Pickrell, 1990;Fourace et al, 1990;Leavitt et al, 1993;Dantata et al, 2006;Flyvbjerg et al, 2007); more research is needed to understand the dynamics and nuances of rail projects so as to contribute to the development of a theory of cost overrun causation.…”

mentioning

confidence: 99%

Off the rails: The cost performance of infrastructure rail projects

Love

Zhou

Edwards

et al. 2017

Transportation Research Part A: Policy and Practice

View full text Add to dashboard Cite

Governments in Australia place great emphasis on the development and expansion of their rail networks to improve productivity and service the increasing needs and demands from businesses and commuters. A case study approach is used to analyze the cost performance of 16 rail projects constructed by a contractor between 2011 and 2014, which ranged from AU$3.4 to AU$353 million. Findings indicate that scope changes during construction were the key contributors that lead to the amendment of each project's original contractual value. As a result, there is a need for public and private sector asset owners to establish a cost contingency using a probabilistic rather than a deterministic approach to accommodate the potential for scope changes during construction. To improve cost certainty during the construction of rail projects, it is suggested that use of collaborative forms of procurement juxtaposed with the use of Building Information Modelling and Systems Information Modelling are implemented. The utilization of such technological and process innovations can provide public and private sector asset owners charged with delivering and maintaining their rail networks with confidence projects can be delivered within budget and are resilient to unexpected events and adaptable to changing needs, uses or capacities.

show abstract

The Accuracy of Hybrid Estimating Approaches: A Case Study of an Australian State Road & Traffic Authority

Cited by 25 publications

References 30 publications

Understanding the Landscape of Overruns in Transport Infrastructure Projects

Understanding the Landscape of Overruns in Transport Infrastructure Projects

Estimating a Unit Price for Roads Maintenance Activities Using Exponential Robust Regression

Off the rails: The cost performance of infrastructure rail projects

Contact Info

Product

Resources

About