No description available.

No description available.

Data relating to the bids for 384 roads contracts and 190 buildings contracts and a library of individual unit prices were obtained. The normality or near normality of the distribution of bids for buildings and roads contracts is established. This allows the relationship between mean and lowest bids to be defined using normal order statistics. It also permits the application of outlier tests to be used in identifying unrealistically low bids. The average mean standardised bids of contractors have a strong negative correlation with the contractor's success ratio. This allows contractors to predict success ratios of others using their mean-standardised bids. The data required for this is not limited to the competitions in which the contractor himself enters. Contractors have different behaviour patterns, some with disproportionate numbers of high or low bids and others behave randomly. These behaviour features correlate well with the average mean-standardised bids. Graphs of the cumulative sum of (bid-mean bid)/mean bid are useful in identifying contractors who are seeking work and those who are not. These can be used to identify serious rivals for particular contracts. Contractors have different sensitivity of success ratio to changes in bid value thus indicating different market judgements. Contractors also have different trends within their standardised bids to contract value. This only affects success ratios in extreme cases. Designers have accuracies of standard deviations of 16.63% and 20.14% for predicting the lowest bid of buildings and roads contracts respectively. Price models based on multiple regression analysis produce similar accuracies for comparable construction works. The tender price prediction system developed, based on a library of, untt prices and inflation indices achieved a standard deviation of 8,30% in predicting the mean bid and 11.08% in predicting the lowest bid for roads contracts. This could be improved with more data in the price library but nevertheless is a substantial improvement on the results achieved by designer's estimating.

No description available.

No description available.

The problem of determining an appropriate procurement form for the management of a construction project has been surrounded by controversy and strongly held opinions. The work reported here attempts to indicate some rational basis for choice in this decision by identifying those factors which significantly affect project performance, with particular reference to the distinctions between design build and traditional procurement forms. Two basic propositions are addressed by the work. The former is that design build forms perform better than traditional forms. This view is based on the conventional, construction industry view of the factors which affect performance. The latter is that contextual factors and the management and organisation of the construction process are the major determinants of project performance. This view stems from the application of management theory to the construction process and takes into account more and diverse variables than the conventional view. The factors which affect construction project performance are identified by reviewing three basic areas which are fundamental to the research. The first is the construction process and the way it has been treated and analysed in the past, which has been based around the traditional form of organisation. The second is the perceptions held concerning the design build process and how this procurement form has developed over recent years. A taxonomy of design build organisations is presented. Finally, the literature concerning project management, in general and specifically applied to the construction process, is reviewed and those factors which have been identified as affecting project performance identified. Following on is a review of performance measures which have previously been adopted. Based on this review a number of measures are chosen to compare performance (a mixture of objective and subjective measures). The foregoing leads to the situation where two research models are proposed and tested, by the formulation of related hypotheses, in two separate phases of the research process. A sample of 47 projects was used in the initial phase of the work and this was followed up by 27 detailed case studies in the subsequent phase. The data collected are analysed using partial correlation analysis as the principal analytic tool and the main results are reported below. The primary conclusion to be drawn is that procurement form is not a good predictor of performance. In general, the management, organisation and contextual variables are found to be more strongly associated with performance. Specifically, increased client complexity and dependence are found to be associated with reduced performance, as are increased project complexity and uncertainty. Document certainty and completeness and the degree of competition in letting construction works are all factors found to affect performance. Familiarity and differentiation are organisational factors which are found to be strongly associated with performance. Finally, it is shown that different procurement forms can be located on a structure grid and that those organisations which are appropriately located are associated with higher levels of performance.

No description available.

No description available.

No description available.

No description available.