Modeling uncertainty with an integrated simulation system.

Uncertainty inevitably affects the performance of a construction project. The ability to identify uncertainty and quantitatively evaluate its impact on the project performance can significantly enhance the accuracy and reliability of a project plan. This paper describes a methodology to classify, model, and reduce uncertainty. This method was implemented within an integrated simulation framework capable of capturing physical features of the facility to be constructed, uncertainty in the working environment, and the construction processes. A "virtual" steel fabrication shop model was developed using the proposed framework to model uncertainty in a steel fabrication shop environment. The artificial neural network (ANN) modeling technique, which plays a significant role in the simulation model, was used to model activity duration based on the identified productivity influencing factors and data collected through a time study project conducted in the fabrication shop. The virtual shop model with the embedded ANN model proved to be more accurate than the traditional approach of modeling activity duration using statistical distributions. [ABSTRACT FROM AUTHOR]