Rework in Civil Infrastructure Projects: Determination of Cost Predictors

Within Australia, civil engineering works continue to meet the insatiable demand for new infrastructure despite project complexity and cost and schedule overruns. A significant factor that can contribute to such overruns is rework; yet to date research into the root causes and consequential costs of rework in civil infrastructure projects has been limited. Using a questionnaire survey, rework costs and probable causes were obtained from 115 civil infrastructure projects. Stepwise multiple regression was then used to determine the significant variables that contributed to rework. The regression model revealed that the following five significant predictors accounted for 25% of the variance in total rework cost: (1) ineffective use of information technologies; (2) excessive client involvement in the project; (3) lack of clearly defined working procedures; (4) changes made at the request of the client; and (5) insufficient changes initiated by the contractor to improve quality. The findings also revealed that mean total rework costs were 10% of the contract value for the sample. Interestingly, the extent of rework experienced was significantly correlated with project cost and schedule growth (p<0.01). It is suggested that future work is required to determine the underlying factors that contribute to rework in civil infrastructure projects before effective preventive strategies can be identified.