Uncertainty robustness in construction scheduling

The uncertainty assessment of activities’ duration and its impact on the total project duration is certainly an important step towards reducing the duration uncertainty of projects and their delivery date. Since each construction project is unique, this work utilizes stochastic simulation to evaluate the uncertainty of the project delivery date. The simulation is based on network time planning with stochastic durations. The present trend of shifting from the "Quality control" to the "Quality Assurance" paradigm by applying robust production processes is transposed from the manufacturing industry to construction scheduling. A quality yardstick for time planning is proposed and described. Previously, a study was conducted to determine the main influences to the uncertainty of the project duration utilizing Stochastic Simulation and the Design of Experiments Process. Some specific characteristics have shown great importance. A computer assisted procedure for the reduction of the project duration uncertainty is proposed and validated in 4 real case studies. Two expressions are also proposed: The first quantifies the duration uncertainty of single activities, whereas the second indicates the influence of single activities’ duration uncertainty in the total project duration uncertainty. Finally, a cost-benefit analysis of this procedure is carried out for the construction sector and its scope of utilization is determined