Quantifying schedule risk in construction projects using Bayesian belief networks

Delays on construction projects cause financial losses for project stakeholders in developing countries. This paper describes how Bayesian belief network (BBN) is applied to quantify the probability of construction project delays in a developing country. Sixteen factors were identified through a questionnaire survey of 166 professionals. Eighteen cause-effect relationships among these factors were obtained through expert interview survey to develop a belief network model. The validity of the proposed model is tested using two realistic case studies. The findings of the study revealed that financial difficulties of owners and contractors, contractor's inadequate experience, and shortage of materials are the main causes of delay on construction projects in Vietnam. The results encourage practitioners to benefit from the BBNs. This approach is general and, as such, it may be applied to other construction projects with minor modifications. © 2008 Elsevier Ltd and IPMA.