Risk of Quantity Increase in Vietnamese Construction Projects

Quantity increase is a common problem in the construction sector. The main purpose of this study is to determine potential factors causing quantity increase in construction projects using governmental budgets. This study then points out some relevant solutions to reduce the occurrence of quantity increase. There were totally 18 factors causing quantity increase found from the literature review and expert's opinion. A structured questionnaire, which was designed with the 5-point Likert scale, was used to collect data. The results of analysis showed that these factors have strong impact on the quantity increase of the construction projects. The consensus level between project parties in ranking the factors of quantity increase according to frequency index, severity index, and importance index are quite high. In addition, the risk of cost due to the quantity increases was quantitatively analyzed by using Monte Carlo simulation through 21 school construction projects.