Time risk assessment framework for highway projects in Nigeria

Abstract

Time overrun on construction projects continue to linger and is substantial in both developed and developing countries. Numerous risk management standards and risk assessment models have been developed to identify and minimise risks in improving time performance of construction projects. However, such attempts do not seem parallel with the improvements required. Hence, this study aims to develop a two dimensional risk assessment framework for highway rehabilitation projects by integrating probability and severity measures of significant risk factors with organisational risk management capability measures to derive risk magnitude index for highway rehabilitation projects. To accomplish this aim, quantitative survey research design was employed. Two sets of questionnaires were developed and administered to construction professionals and organisations that are directly involved in the execution of the sampled design, bid and build highway rehabilitation projects in Nigeria. List and classification of risk factors were validated by Delphi survey and data collected from the questionnaire survey were analysed by the application of Fuzzy set theory, analysis of variance and spearman rank correlation. Results of the data analysis reveal that the overall risk indices on rehabilitation projects executed by different construction organisations are significantly different but have strong inverse relationship with the risk management maturity indices of the construction organisations. Based on this relationship, a decision matrix was developed as a tool to combine overall risk indices with risk management maturity indices to derive risk magnitude indices for all risk factors and project level risk. The inputs, concepts, techniques and tools leading to this result formed the basis for the development of the proposed risk assessment framework. The framework was validated through structured interview with a team of experts. The validation team strongly agreed with the logical soundness and completeness of the proposed two dimensional risk assessment framework, affirming the framework to be practicable and acceptable for assessing time risks on highway rehabilitation projects in Nigeria. The framework can thus be adopted to ensure a complete and comprehensive assessment of risk on highway rehabilitation projects.