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Francis K Adams - One of the best experts on this subject based on the ideXlab platform.

  • risk perception and bayesian analysis of international Construction Contract risks the case of payment delays in a developing economy
    International Journal of Project Management, 2008
    Co-Authors: Francis K Adams
    Abstract:

    Abstract Although subjective probabilities and Bayesian methods are applied successfully in other industries to manage “subjective” risks similar to those encountered in Construction Contracts, very little is reported on the application of such methods for analysing Construction Contract risks, which are generally subjective in nature. Predominant industrial practice seems to be the use of arbitrary contingency figures, which are often subject to individual perceptions of risks, to give an overall impression of Contract risks. This paper presents an application of an expert elicitation model and Bayesian methods to the analysis of the risk of payment delays in international Contracts set in a developing economy, and a determination of how differing perceptions about risks affect estimates about the risk. Expert opinions about the risk of payment delays in an international Contract set in Ghana are transformed into prior distributions about the risk using the relative likelihood method and combined with sample information about the risk for a Bayesian analysis of the risk. Results of the study validates the elicitation model applied and reveal that although Construction professionals to have difficulty estimating intermediate and tail values of probability distributions, expert elicitation and Bayesian analysis can be applied to Construction Contract risks, as part of a more systematic management of Contract risks, to achieve better rigour in risk analysis. It further confirms the assertion that differences exists in the belief functions and hence the risk estimates of experts from different socio-cultural backgrounds. Effective strategies for systematically analysing Contract risks in international Contracts must therefore consider the impact of risk perception in the risk management process.

  • expert elicitation and bayesian analysis of Construction Contract risks an investigation
    Construction Management and Economics, 2006
    Co-Authors: Francis K Adams
    Abstract:

    Formal risk analysis techniques applied in managing Construction project risks tend to focus on risks that lend themselves to ‘objective’ methods of economic analysis. Although subjective probabilities and Bayesian methods are applied successfully in other industries to manage ‘subjective’ risks similar to those encountered in Construction Contracts, very little is reported on the application of such methods for analysing risks in Construction Contracts. An investigation has been carried out into using subjective expert opinions and Bayesian methods in Construction Contract risk analysis. The elicitation of expert opinions about the risk of encountering adverse ground conditions on Construction sites is examined. Prior distributions of expert opinions about the risk form the critical component in the Bayesian analysis of risk. The conclusion of this is that although Construction professionals have difficulty estimating intermediate and tail values of probability distributions, elicitation techniques can b...

Martin Skitmore - One of the best experts on this subject based on the ideXlab platform.

  • on the distribution of bids for Construction Contract auctions
    Science & Engineering Faculty, 2017
    Co-Authors: Pablo Ballesterosperez, Martin Skitmore
    Abstract:

    The statistical distribution representing bid values constitutes an essential part of many auction models and has involved a wide range of assumptions, including the Uniform, Normal, Lognormal and Weibull densities. From a modelling point of view, its goodness is defined by how well it enables the probability of a particular bid value to be estimated – a past bid for ex-post analysis and a future bid for ex-ante (forecasting) analysis. However, there is no agreement to date of what is the most appropriate form and empirical work is sparse. Twelve extant Construction datasets from four continents over different time periods are analysed in this paper for their fit to a variety of candidate statistical distributions assuming homogeneity of bidders (ID not known). The results show there is no one single fit-all distribution, but that the 3p Log-Normal, Frechet/2p Log-Normal, Normal, Gamma and Gumbel generally rank the best ex-post, and the 2p Log-Normal, Normal, Gamma and Gumbel the best ex-ante – with ex-ante having around three to four times worse fit than ex-post. Final comments focus on the results relating to the third and fourth standardised moments of the bids and a post-hoc rationalisation of the empirical outcome of the analysis.

  • quick abnormal bid detection method for Construction Contract auctions
    Journal of Construction Engineering and Management-asce, 2015
    Co-Authors: Pablo Ballesterosperez, Martin Skitmore, Raj Das, Maria Luisa Del Campohitschfeld
    Abstract:

    Noncompetitive bids have recently become a major concern in both public and private sector Construction Contract auctions. Consequently, several models have been developed to help identify bidders potentially involved in collusive practices. However, most of these models require complex calculations and extensive information that is difficult to obtain. The aim of this paper is to utilize recent developments for detecting abnormal bids in capped auctions (auctions with an upper bid limit set by the auctioner) and extend them to the more conventional uncapped auctions (where no such limits are set). To accomplish this, a new method is developed for estimating the values of bid distribution supports by using the solution to what has become known as the German Tank problem. The model is then demonstrated and tested on a sample of real Construction bid data, and shown to detect cover bids with high accuracy. This paper contributes to an improved understanding of abnormal bid behavior as an aid to detecting and monitoring potential collusive bid practices.

  • identifying non competitive bids in Construction Contract auctions
    Omega-international Journal of Management Science, 2002
    Co-Authors: Martin Skitmore
    Abstract:

    Construction Contract auctions are characterised by (1) anticipated high outliers due to the presence of non-competitive bids, (2) very small samples and (3) uncertainty of the appropriate underlying density function model of the bids. This paper describes the simultaneous identification of high outliers and density function by systematically identifying and removing candidate (high) outliers and examining the composite goodness-of-fit of the resulting reduced samples with the normal and lognormal density functions. Six different identification strategies are tested empirically by application, both independently and in pooled form, to several sets of auction data gathered from around the world. The results indicate the normal density to be the most appropriate model and a multiple of the auction standard deviation to be the best identification strategy.

  • a multivariate approach to Construction Contract bidding mark up strategies
    Journal of the Operational Research Society, 1994
    Co-Authors: Martin Skitmore, John Pemberton
    Abstract:

    A multivariate approach to Contract bidding strategies in the Construction industry is presented. This represents a radical departure from previous work in the field by using all available data on competing bidders. ‘Optimal’, ‘no loss’ and ‘break even’ mark-up strategies are derived and methods of parameter estimation proposed. A case study shows how the three strategic mark-up values are calculated against known competitors.

Kmj Harmon - One of the best experts on this subject based on the ideXlab platform.

  • conflicts between owner and Contractors proposed intervention process
    Journal of Management in Engineering, 2003
    Co-Authors: Kmj Harmon
    Abstract:

    The parties of a Construction Contract, the owner and Contractor, are a society with a complex set of interrelated relationships requiring cooperation and collaboration to coordinate time, resources, and communication. The main aim of the involved parties in a project's Construction is to have a successful project constructed in accordance with plans and specifications, within the time and cost originally anticipated. The success of a project depends on a number of variables, not the least of which is how the organizations approach problems and conflicts. However, the adversarial atmosphere that pervades the industry can prevent the parties from reaching their goal. An intervention process is proposed--a combination of partnership and mediation, to prevent and resolve dispute prior to Contract close-out.

  • conflicts between owner and Contractors proposed intervention process
    Journal of Management in Engineering, 2003
    Co-Authors: Kmj Harmon
    Abstract:

    The parties of a Construction Contract, the owner and Contractor, are a society with a complex set of interrelated relationships requiring cooperation and collaboration to coordinate time, resources, and communication. The main goal of the parties involved in a project’s Construction is to have a successful project constructed in accordance with the plans and specifications, within the time and cost originally anticipated. The success of a project depends on a number of variables, not the least of which is how the organizations approach problems and conflicts. However, the adversarial atmosphere that infects the industry can prevent the parties from reaching their goal. This paper proposes an intervention process, a combination of partnership and mediation, to prevent and resolve dispute prior to Contract close-out.

Soliman A. Almohawis - One of the best experts on this subject based on the ideXlab platform.

  • setting Construction Contract duration public projects in saudi arabia
    Building Research and Information, 1994
    Co-Authors: Soliman A. Almohawis, Ahmad S Alsultan
    Abstract:

    A detailed survey of the public agencies revealed three patterns for setting CCD and the growing need for developing formal and systematic procedures.

  • Evaluating the general conditions of a Construction Contract
    International Journal of Project Management, 1994
    Co-Authors: Abdulaziz A. Bubshait, Soliman A. Almohawis
    Abstract:

    Abstract International Construction Contractors are often faced with the situation of working in an unfamiliar Construction environment. One potential source of risk is the Contractual requirements embodied in the general conditions of Contracts. The paper presents a simple quantitative method for evaluating the general conditions of a Construction Contract. 11 attributes were used in this evaluation: clarity, conciseness, completeness, internal and external consistency, practicality, fairness, effect on quality, cost, schedule, and safety. The procedure can also be used to assess the risk level associated with the general conditions.

Paul M Goodrum - One of the best experts on this subject based on the ideXlab platform.

  • using parametric modeling to estimate highway Construction Contract time
    Transportation Research Record, 2016
    Co-Authors: Dong Zhai, Yongwei Shan, Roy E Sturgill, Timothy R B Taylor, Paul M Goodrum
    Abstract:

    Federal regulations require that state transportation agencies have written procedures for setting the Construction Contract time for highway projects. Since the institution of those regulations, state agencies have used a variety of methods to estimate and set Contract time. FHWA recommends the use of methods based on production rate and activity precedence and logic in this process. For years, the Kentucky Transportation Cabinet used a system based around these requirements and recommendations only to find that the system produced estimates varying widely from actual Construction times. The use of parametric modeling and historic Contract times produced a system that more accurately estimates Contract times and with an associated Microsoft Excel–based tool is more user friendly. This approach used project cost and bid item quantity data in multivariate regression–based modeling to develop a set of equations that provide the Kentucky Transportation Cabinet with Contract time estimates for projects in a m...