A multi-objective probabilistic-based method to determine optimum allocation of time buffer in construction schedules

The use of buffers as a production strategy entails establishing a balance between theory and practice. In the complex environment of construction projects, this balance establishment requires an optimization process. It involves multiple criteria necessary to project success. So far, the heuristics and analytics developed, either fail to provide a clear logic to solve the multi-objective problem or revolve only around the mathematical solutions. This research proposes a Multi-objective Probabilistic-Based Buffer Allocation method (MPBAL) based on a goal-seeking optimization approach that uses a visual presentation of the mathematical optimization results to involve the preference of the project decision-makers in the final solution. MPBAL was tested against the records of a bridge construction project. The results were compared to the findings from a numerical analysis obtained by an extensive Monte Carlo study. The comparison indicated the high quality of MPBAL optimization analysis, while it utilizes an approximate combinatorial analytic method to avoid the errors typical of the numerical analysis.