Factors affecting the accuracy of engineers' estimates

Emerging sciences, such as conceptual cost estimating, seem to have to go through two phases. The first phase involves reducing the field of study down to its basic ingredients - from systems development to technological development (techniques) to theoretical development. The second phase operates in the direction in building up techniques from theories, and systems from techniques. Cost estimating is clearly and distinctly still in the first phase. A great deal of effort has been put into the development of both manual and computer based cost estimating systems during this first phase and, to a lesser extent, the development of a range of techniques that can be used (see, for instance, Ashworth & Skitmore, 1986). Theoretical developments have not, as yet, been forthcoming. All theories need the support of some observational data and cost estimating is not likely to be an exception. These data do not need to be complete in order to build theories. As it is possible to construct an image of a prehistoric animal such as the brontosaurus from only a few key bones and relics, so a theory of cost estimating may possibly be found on a few factual details. The eternal argument of empiricists and deductionists is that, as theories need factual support, so do we need theories in order to know what facts to collect. In cost estimating, the basic facts of interest concern accuracy, the cost of achieving this accuracy, and the trade off between the two. When cost estimating theories do begin to emerge, it is highly likely that these relationships will be central features. This paper presents some of the facts we have been able to acquire regarding one part of this relationship - accuracy, and its influencing factors. Although some of these factors, such as the amount of information used in preparing the estimate, will have cost consequences, we have not yet reached the stage of quantifying these costs. Indeed, as will be seen, many of the factors do not involve any substantial cost considerations. The absence of any theory is reflected in the arbitrary manner in which the factors are presented. Rather, the emphasis here is on the consideration of purely empirical data concerning estimating accuracy. The essence of good empirical research is to .minimize the role of the researcher in interpreting the results of the study. Whilst space does not allow a full treatment of the material in this manner, the principle has been adopted as closely as possible to present results in an uncleaned and unbiased way. In most cases the evidence speaks for itself. The first part of the paper reviews most of the empirical evidence that we have located to date. Knowledge of any work done, but omitted here would be most welcome. The second part of the paper presents an analysis of some recently acquired data pertaining to this growing subject.

An expert system for the strategic planning of construction projects

This paper describes the instigation and development of an expert system to aid in the strategic planning of construction projects. The paper consists of four parts - the origin of the project, the development of the concepts needed for the proposed system, the building of the system itself, and assessment of its performance. The origin of the project is outlined starting with the Japanese commitment to 5th generation computing together with the increasing local reaction to theory based prescriptive research in the field. The subsequent development of activities via the Alvey Commission and the RICS in conjunction with Salford University are traced culminating in the proposal and execution of the first major expert system to be built for the UK construction industry, subsequently recognised as one of the most successful of the expert system projects commissioned under the Alvey programme

Accuracy in estimating

Several methods of estimating the costs or price of construction projects are now available for use in the construction industry. It is difficult due to the conservative approach of estimators and quantity surveyors, and the fact that the industry is undergoing one of its deepest recessions this century, to implement any changes in these processes. Several methods have been tried and tested and probably discarded forever, whereas other methods are still in their infancy. There is also a movement towards greater use of the computer, whichever method seems to be adopted. An important consideration with any method of estimating is the accuracy by which costs can be calculated. Any improvement in this consideration will be welcomed by a11 parties, because existing methods are poor when measured by this criteria. Estimating, particularly by contractors, has always carried some mystic, and many of the processes discussed both in the classroom and in practice are little more than fallacy when properly investigated. What makes an estimator or quantity surveyor good at forecasting the right price? To what extent does human behaviour influence or have a part to play? These and some of the other aspects of effective estimating are now examined in more detail.

Normanton2020

Normanton2020 This exhibition showcases the work of 3rd -4th year undergraduate landscape architecture, architecture, Interior Design, Environmental Engineering, Civil Engineering students in response to issues of sustainability in the Gulf of Carpentaria town of Normanton. 16 students and four staff set off on a 2488km journey to undertake the second half of the Carpentaria Project (following Linking Karumba: Creating Sustainable Connections 2008), in the other Carpentaria Shire town of Normanton. This project, Get EnGulfed: Normanton 2020, looked back and forwards to propose strategies strengthening local and regional identities. Our project partners recognised the need for a strategic approach to developing future visions for Normanton’s growth as a socially, culturally, economically and ecologically sustainable town in the decade to 2020. They proposed: Project aims to foster: • Enhanced liveability; • A strengthened expression of town identity; • Expanded sustainable tourism. Primary challenges & opportunities: • Remoteness; • Two seasons: wet & dry; • Local economy; • Society and Cultural Heritage. The Exhibition Four groups of four students produced four strategic planning and design options toward this future: Mud Maps of Normanton: Rhys Belnap, AJ Humphries, Amos Shirreff, Haiku Van Keuk Normanton: Stay Another Day: Belle Dalton, Tom Jordan, Josh Nielsen, Carla Ramsland The Sweet Spot on the Savannah Way: Daniel Lapham, Yvonne Phillips, Patrick Poon, Dan Young Resilience Through Diversity: Jillian Kenny, Tania Metcher, Stephen Orr, Evan Thompson

Get EnGulfed: Normanton2020

Get EnGulfed: Normanton2020 This exhibition showcases the work of 3rd -4th year undergraduate landscape architecture, architecture, Interior Design, Environmental Engineering, Civil Engineering students in response to issues of sustainability in the Gulf of Carpentaria town of Normanton. It presented the work to QUT staff from across the university, as well as industry partners and invited guests. 16 students and four staff set off on a 2488km journey to undertake the second half of the Carpentaria Project (following Linking Karumba: Creating Sustainable Connections 2008), in the other Carpentaria Shire town of Normanton. This project, Get EnGulfed: Normanton 2020, looked back and forwards to propose strategies strengthening local and regional identities. Our project partners recognised the need for a strategic approach to developing future visions for Normanton’s growth as a socially, culturally, economically and ecologically sustainable town in the decade to 2020. They proposed: Project aims to foster: • Enhanced liveability; • A strengthened expression of town identity; • Expanded sustainable tourism. • Primary challenges & opportunities: • Remoteness; • Two seasons: wet & dry; • Local economy; • Society and Cultural Heritage. The Exhibition Four groups of four students produced four strategic planning and design options toward this future: Mud Maps of Normanton: Rhys Belnap, AJ Humphries, Amos Shirreff, Haiku Van Keuk Normanton: Stay Another Day: Belle Dalton, Tom Jordan, Josh Nielsen, Carla Ramsland The Sweet Spot on the Savannah Way: Daniel Lapham, Yvonne Phillips, Patrick Poon, Dan Young Resilience Through Diversity: Jillian Kenny, Tania Metcher, Stephen Orr, Evan Thompson

Brownfield re-development : Perceptions and risk mitigation strategies

Scarcity of large parcels of land in well-serviced areas has motivated people to re-develop brownfield land. Most of brownfield land has high risk of contamination from wide range of industrial activities such as gas works, factories, railway land and waste tips. In addition, people who live in brownfield re-development areas may be exposed to health hazards. This paper discusses public perceptions on the brownfield sites and also the risk and mitigation strategy to promote brownfield re-development. Data is gathered from face to face survey of fifty respondents who work in Brisbane Central Business District (CBD) and interview with an expert on remediation of contaminated land. From this preliminary study, it is found that majority of the population are not aware of any brownfield sites near their residence and those who are aware showed very little concern on their proximity to the site. Further discussion on the paper based on a simple cross tabulation analysis. The main risk mitigation strategy of re-development of brownfield site is by updating the registration through Environmental Management Register (EMR) and Contaminated Land Register (CLR). In addition, insurance may offer to cover cost overruns on remediation cost.

Linking Karumba : Creating Sustainable Connections

Linking Karumba: Creating Sustainable Connections This exhibition showcases the work of 3rd -4th year undergraduate landscape architecture, architecture, Industrial Design, Environmental Engineering, Civil Engineering students in response to issues of sustainability in the Gulf of Carpentaria town of Karumba. It presented the work to the Karumba and Carpentaria Shire community. 16 students and four staff set off on a 2488km journey to undertake the first half of the Carpentaria Project: a fortnight-long strategic planning project entitled Linking Karumba to encourage social, economic, environmental and cultural linkages across the town. Karumba, along with the nearby town of Normanton, is one of Queensland’s most remote settlements. Its economy is based on fishing, tourism, and mining. It has two centres, 2.5km apart by river, or 9km by road. This physical disconnect was identified by Carpentaria Shire Council (CSC) and the Karumba Progress Association (KPA) as a source of socio-cultural disconnection, which formed the basis of our project brief. Student designs were highly responsive to the character of Karumba’s culture and environment, indicating remarkable levels of immersion, and attracting $830 000 in Qld. state government funding for implementation. The Exhibition Four groups of four students produced four strategic planning and design options toward this future: Make the Switch: Alice Anonuevo, Michael Marriott, Carla Priestley & Grant Harvey Realigning the Systems: Claudia Bergs, Rebecca Stephens, Anna Coulson & Lois Kerrigan Diversification of Experience: Rebecca North, Kyle Bush, Debra Sullivan & Jenna Green The River is the Main Street: Ashley Nicholson, Monica Kuiken, Dean Bowen & Bill Schild

QUT Linking Karumba Project

QUT Linking Karumba Project This exhibition showcases the work of 3rd -4th year undergraduate landscape architecture, architecture, Industrial Design, Environmental Engineering, Civil Engineering students in response to issues of sustainability in the Gulf of Carpentaria town of Karumba. It presented the final, polished set of work to the Karumba and Carpentaria Shire community, following revisions in line with feedback from the 2008 exhibition. 16 students and four staff set off on a 2488km journey to undertake the first half of the Carpentaria Project: a fortnight-long strategic planning project entitled Linking Karumba to encourage social, economic, environmental and cultural linkages across the town. Karumba, along with the nearby town of Normanton, is one of Queensland’s most remote settlements. Its economy is based on fishing, tourism, and mining. It has two centres, 2.5km apart by river, or 9km by road. This physical disconnect was identified by Carpentaria Shire Council (CSC) and the Karumba Progress Association (KPA) as a source of socio-cultural disconnection, which formed the basis of our project brief. Student designs were highly responsive to the character of Karumba’s culture and environment, indicating remarkable levels of immersion, and attracting $830 000 in Qld. state government funding for implementation. The Exhibition Four groups of four students produced four strategic planning and design options toward this future: Make the Switch: Alice Anonuevo, Michael Marriott, Carla Priestley & Grant Harvey Realigning the Systems: Claudia Bergs, Rebecca Stephens, Anna Coulson & Lois Kerrigan Diversification of Experience: Rebecca North, Kyle Bush, Debra Sullivan & Jenna Green The River is the Main Street: Ashley Nicholson, Monica Kuiken, Dean Bowen & Bill Schild

Construction Prices : the Market Effect

Teachers of construction economics and estimating have for a long time recognised that there is more to construction pricing than detailed calculation of costs (to the contractor). We always get to the point where we have to say "of course, experience or familiarity of the market is very important and this needs judgement, intuition, etc". Quite how important is the matter in construction pricing is not known and we tend to trivialise its effect. If judgement of the market has a minimal effect, little harm would be done, but if it is really important then some quite serious consequences arise which go well beyond the teaching environment. Major areas of concern for the quantity surveyor are in cost modelling and cost planning - neither of which pay any significant attention to the market effect. There are currently two schools of thought about the market effect issue. The first school is prepared to ignore possible effects until more is known. This may be called the pragmatic school. The second school exists solely to criticise the first school. We will call this the antagonistic school. Neither the pragmatic nor the antagonistic schools seem to be particularly keen to resolve the issue one way or the other. The founder and leader of the antagonistic school is Brian Fine whose paper in 1974 is still the basic text on the subject, and in which he coined the term 'socially acceptable' price to describe what we now recognise as the market effect. Mr Fine's argument was then, and is since, that the uncertainty surrounding the contractors' costing and cost estimating process is such that the uncertainty surrounding the contractors' cost that it logically leads to a market-orientated pricing approach. Very little factual evidence, however, seems to be available to support these arguments in any conclusive manner. A further, and more important point for the pragmatic school, is that, even if the market effect is as important as Mr Fine believes, there are no indications of how it can be measured, evaluated or predicted. Since 1974 evidence has been accumulating which tends to reinforce the antagonists' view. A review of the literature covering both contractors' and designers' estimates found many references to the use of value judgements in construction pricing (Ashworth & Skitmore, 1985), which supports the antagonistic view in implying the existence of uncertainty overload. The most convincing evidence emerged quite by accident in some research we recently completed with practicing quantity surveyors in estimating accuracy (Skitmore, 1985). In addition to demonstrating that individual quantity surveyors and certain types of buildings had significant effect on estimating accuracy, one surprise result was that only a very small amount of information was used by the most expert surveyors for relatively very accurate estimates. Only the type and size of building, it seemed, was really relevant in determining accuracy. More detailed information about the buildings' specification, and even a sight to the drawings, did not significantly improve their accuracy level. This seemed to offer clear evidence that the constructional aspects of the project were largely irrelevant and that the expert surveyors were somehow tuning in to the market price of the building. The obvious next step is to feed our expert surveyors with more relevant 'market' information in order to assess its effect. The problem with this is that our experts do not seem able to verbalise their requirements in this respect - a common occurrence in research of this nature. The lack of research into the nature of market effects on prices also means the literature provides little of benefit. Hence the need for this study. It was felt that a clearer picture of the nature of construction markets would be obtained in an environment where free enterprise was a truly ideological force. For this reason, the United States of America was chosen for the next stage of our investigations. Several people were interviewed in an informal and unstructured manner to elicit their views on the action of market forces on construction prices. Although a small number of people were involved, they were thought to be reasonably representative of knowledge in construction pricing. They were also very well able to articulate their views. Our initial reaction to the interviews was that our USA subjects held very close views to those held in the UK. However, detailed analysis revealed the existence of remarkably clear and consistent insights that would not have been obtained in the UK. Further evidence was also obtained from literature relating to the subject and some of the interviewees very kindly expanded on their views in later postal correspondence. We have now analysed all the evidence received and, although a great deal is of an anecdotal nature, we feel that our findings enable at least the basic nature of the subject to be understood and that the factors and their interrelationships can now be examined more formally in relation to construction price levels. I must express my gratitude to the Royal Institution of Chartered Surveyors' Educational Trust and the University of Salford's Department of Civil Engineering for collectively funding this study. My sincere thanks also go to our American participants who freely gave their time and valuable knowledge to us in our enquiries. Finally, I must record my thanks to Tim and Anne for their remarkable ability to produce an intelligible typescript from my unintelligible writing.