J.H.M. Tah

A proposal for construction project risk assessment using fuzzy logic

The construction industry is plagued by risk and often has suffered poor performance as a result. There are a number of risk management techniques available to help alleviate this, but usually these are based on operational research techniques developed in the 1960s, and for the most part have failed to meet the needs of project managers. In this paper, a hierarchical risk breakdown structure representation is used to develop a formal model for qualitative risk assessment. A common language for describing risks is presented which includes terms for quantifying likelihoods and impacts so as to achieve consistent quantification. The relationships between risk factors, risks and their consequences are represented on cause and effect diagrams. These diagrams and the concepts of fuzzy association and fuzzy composition are applied to identify relationships between risk sources and the consequences for project performance measures. A methodology for evaluating the risk exposure, considering the consequences in terms of time, cost, quality, and safety performance measures of a project based on fuzzy estimates of the risk components is presented.

A fuzzy approach to constuction project risk assessment and analysis: construction project risk management system

Abstract The construction industry is plagued by risk, and poor performance has often been the result. Although risk management techniques have been applied, the lack of a formalised approach has produced inconsistent results. In this paper, a hierarchical risk breakdown structure is described to represent a formal model for qualitative risk assessment. The relationships between risk factors, risks, and their consequences are represented on case and effect diagrams. Risk descriptions and their consequences can be defined using descriptive linguistic variables. Using fuzzy approximation and composition, the relationships between risk sources and the consequences on project performance measures can be identified and quantified consistently.

Towards a framework for project risk knowledge management in the construction supply chain

Abstract The shortcomings of current project risk management processes, tools and techniques, are identified and the case for the application of knowledge management philosophies and techniques to project risk management is made. A common language for describing risks based on a hierarchical-risk breakdown structure has been developed and it provides the basis for developing a sharable knowledge-driven approach to risk management. This defines generic risk and remedial action descriptive terms, which can then be stored in catalogues. These have been implemented in a database management system to act as a knowledge repository. A prototype system being developed to support the risk management framework is briefly discussed.

Contractor project risks contingency allocation using linguistic approximation

Abstract This paper demonstrates the application of fuzzy set theory to the subjective assessment of risks during tender preparation for the purpose of allocating contingencies. The need for contingency allocation is discussed and relevant project risk factors are identified. A hierarchical risk-breakdown structure for contractor risk assessment and a model for contractor contingency allocation are developed. A brief introduction to fuzzy set theory and the fuzzy risk analysis model to be applied is presented. A simple example is used to illustrate the application of the model in practice. The model is currently being used to develop a knowledge-based system.

RFID-facilitated construction materials management (RFID-CMM) – A case study of water-supply project

Abstract Due to the complex and dynamic nature of the construction industry, construction materials management faces many unique challenges from material planning, ordering, receiving and storing, handling and distribution, site usage and monitoring. Poor materials management has been identified as a major source of low construction productivity, cost overrun and delays. Lack of active, accurate and integrated information flow from material planning, inventory, site use to monitoring and control is a major contributor to such problems. However, it is difficult to obtain such accurate information actively due to the nature of the industry, particularly for large or material intensive projects such as oil or water pipe-laying projects. This paper presents a Radio Frequency Identification system (RFID) facilitated construction material management system which is developed to tackle this problem. This latest technology helps project teams to collect material storage and usage information in an active and accurate way. Additionally, it facilitates the flow of information through the construction materials management process focusing on dynamic material planning, ordering and monitoring. The developed system is being implemented in a water-supply project.

A survey of indirect cost estimating in practice

This paper presents the findings of an investigation into the current practices of estimating the indirect costs involved in tendering for construction work. It shows the results of a survey of current practices and attitudes in seven firms towards the quantification and allocation of general overheads, risk contingencies and profit in a tender. The survey indicates that the methods used are highly subjective and are based on past experience. Quantitative methods involving statistics and probability, even though advocated, are rarely used. This suggests that future methods adopted in a computerized estimating environment should reflect the subjective nature of the process and should be simple enough to be applied.

Trends in built environment semantic Web applications: Where are we today?

Abstract The built environment sector impacts significantly on communities. At the same time, it is the sector with the highest cost and environmental saving potentials provided effective strategies are implemented. The emerging Semantic Web promises new opportunities for efficient management of information and knowledge about various domains. While other domains, particularly bioinformatics have fully embraced the Semantic Web, knowledge about how the same has been applied to the built environment is sketchy. This study investigates the development and trend of Semantic Web applications in the built environment. Understanding the different applications of the Semantic Web is essential for evaluation, improvement and opening of new research. A review of over 120 refereed articles on built environment Semantic Web applications has been conducted. A classification of the different Semantic Web applications in relation to their year of application is presented to highlight the trend. Two major findings have emerged. Firstly, despite limited research about easy-to-use applications, progress is being made from often too-common ontological concepts to more innovative concepts such as Linked Data. Secondly, a shift from traditional construction applications to Semantic Web sustainable construction applications is gradually emerging. To conclude, research challenges, potential future development and research directions have been discussed.

The use of a multi-attribute tool for evaluating accessibility in buildings : the AHP approach

Purpose – The purpose of this article is to develop a quantitative building accessibility assessment model for the construction industry. Design/methodology/approach – The building accessibility assessment criteria are incorporated in a hierarchy structure based on the relevant building regulations and British standards. The analytic hierarchy process (AHP) is employed to determine the priority of the accessibility criteria. A review of the application of AHP is included in the paper. Finally, a case scenario is used to illustrate the method. Findings – This paper provides a methodology to prioritize the building accessibility criteria and to indicate how well a building design meets accessibility requirements quantitatively. Practical limitations/implications – A model is advocated for use by accessibility consultants and building designers to establish a quantitative assessment for building accessibility. It can also be used in the development of accessibility assessment software. Originality/value – This paper presents a novel quantitative building accessibility assessment model.

Information modellng for case-based construction planning of highway bridge projects

Abstract In practice, construction planning and control draws on large-scale project and corporate data repositories, which are often unstructured. This article argues that the development of a large-scale data repository should be the precursor to any case-based reasoning system development. The article presents a large number of conceptual object models, which were developed to identify the attributes and relationships between product and planning information comprehensively, using bridges as a representative product. The models were used to develop a large information repository implemented in a database management system to facilitate real world project information collation, organisation, and management to reflect the large-scale nature of construction projects in practice. The database acts as a source of cases and sub-cases that are retrieved and mapped into a case-base. These cases are considered individually for indexing, matching, retrieval, and validation purposes, facilitating the re-use of parts of multiple cases to construct new project plans. A prototype software model, CBRidge Planner, which was developed and tested with real world project cases to demonstrate the approach is presented.

A critical analysis of Building Information Modelling systems used in construction projects

Construction life cycle project needs to be understood for BIM to be easily integrated.Interoperability is crucial for the uptake of BIM in the construction industry.Supply chain members need to collaborate on projects to deliver BIM compliant projects.There is a need for vendors/manufacturers to adopt a common language in publishing information about BIM software. Building Information Modelling (BIM) is now a global digital technology which is widely believed to have the potential to revolutionise the construction industry. This has been mainly a result of worldwide government initiatives promoting BIM uptake to improve efficiency and quality in delivering construction projects. This push has been accompanied by the release of a tremendous amount of BIM software systems which are now available in the market. Although this can be seen as a positive development, one cannot ignore how it has overwhelmed many professionals who cannot easily distinguish between the uses of these software systems. Previous studies about different BIM systems have generally been limited in scope focusing predominantly on operational issues. This study aims to conduct a comprehensive and critical appraisal of a wide range of BIM software systems currently being used in managing construction project information. To achieve this, five main methods are adopted. These include a systematic review of the literature, a structured questionnaire survey, action learning, focus group discussions and email surveys. It has to be noted that, although it is impossible to examine the totality of BIM systems, the study adopts a holistic approach looking at most of the major BIM system categories and 122 application examples which are common in the architecture, engineering and construction (AEC) industry.