Risk analysis in construction networks using a modified stochastic assignment model

A review of construction network analysis indicates that new methods are ne eded for quantifying risks in project evaluation. The paper proposes a new analytical method, the Modified Stochastic Assignment Model (MSAM), for the prediction of project duration. The proposed method is inspired by a previ ous method used solely in traffic networks, the Stochastic Assignment Model (SAM). The MSAM method applies Clark's approximation to find the longest p roject duration. Two cases arc used to demonstrate the validity and applica tion of the MSAM in construction project evaluations. The accuracy of the M SAM is assessed by comparing it with the Monte Carlo Simulation (MCS). A co mparison of the MSAM with other methods, such as PERT and PNET, has also be en presented. It is found that the new method is an analytical counterpart of the MCS and is very efficient in saving computational time whilst taking full account of the correlations between paths.