Stochastic Scheduling of Linear Construction Sites

Essential basic data of scheduling linear construction sites are subject to stochastically variable influence factors, e.g., weather conditions. To evaluate economical low-cost alternatives which determine the production sequence of segments of a linear site through a projected construction time, a mathematical model is developed which is formulated as a two-stage stochastic linear programming problem and can be solved by standard linear programming methods. Criteria for interpretation and evaluation of model solutions in terms of a time-velocity diagram are derived and illustrated with a simple example problem. By means of stability analysis, risk factors and probability distributions of project duration and cost can be obtained for different construction alternatives to prepare a final decision. It is emphasized that the methodology presented is not seen as an approach to determine the optimal decision, but rather as a tool to facilitate decision making, since this ultimately relies on practical engineering judgment.