Title: PERT vs. Monte Carlo Simulation along with the suitable distribution effect

Authors: Konstantinos A. Kirytopoulos, Vrassidas N. Leopoulos, Viktor K. Diamantas

Addresses: Department of Financial and Management Engineering, University of the Aegean, 31 Fostini Street, Chios, Greece. ' Department of Mechanical Engineering, National Technical University of Athens, 9 Iroon Polytechnioy Street, 15780 Athens, Greece. ' Department of Mechanical Engineering, National Technical University of Athens, 9 Iroon Polytechnioy Street, 15780 Athens, Greece

Abstract: Project schedule development is an iterative process that determines the planned start and finish dates for project activities. Within this process the anticipated project duration is also determined. The primary aim of this paper is to stress the importance of historical information as well as the right distribution selection in activity duration estimating, by comparing the different outcomes of scenarios when historical information is or is not used. The scenarios were implemented on 20 small- and medium-sized construction projects. Both the Programme Evaluation and Review Technique (PERT) and Monte Carlo Simulation (MCS) are used and the results produced under four different scenarios are compared. The first scenario uses standard PERT, while the three remaining scenarios are simulation approaches differentiated in the use of the right distribution or not and in the use of historical information or not. The findings validate that MCS is superior to PERT and moreover expose the difference in the results when the suitable distributions are selected based on accurate historical information compared to when historical information is not available.

Keywords: project risk management; schedule development; programme evaluation and review technique; PERT; Monte Carlo simulation; MCS; activity duration estimating; case study; project scheduling.

DOI: 10.1504/IJPOM.2008.020027

International Journal of Project Organisation and Management, 2008 Vol.1 No.1, pp.24 - 46

Published online: 21 Aug 2008 *

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