Building and Environment 40 (2005) 1244–1254 Judgmental risk analysis process development in construction projects Ahmet O ¨ ztas - Ã ,O ¨ nder O ¨ kmen Civil Engineering Department, University of Gaziantep, Gaziantep, Turkey Received 16 June 2003; accepted 22 October 2004 Abstract Various risks and uncertainties exist in construction projects. These may not only prevent the projects to be completed within budget and time limit, but also threaten the quality, safety and operational needs. In this context, risk analysis processes are the systematic methods to analyze the potential project risks and develop risk response strategies in order to cope with risks and achieve the desired objectives. This study proposes a new schedule risk analysis method named as judgmental risk analysis process (JRAP) and offers a different project duration equation through JRAP. The process (JRAP) can be defined as a pessimistic risk analysis methodology or a hypothesis based on Monte Carlo simulation that is effective in uncertain conditions due to its capability of converting uncertainty to risk judgmentally in construction projects. A case study has also been developed to show how the proposed process is applied on a construction project and to prove its validity. r 2004 Published by Elsevier Ltd. Keywords: Risk; Risk analysis; Monte Carlo simulation; Schedule analysis; Construction management 1. Introduction Each construction project has unique features that differentiate it from even resembling projects. Construc- tion techniques, design, contract types, liabilities, weath- er, soil conditions, politic-economic environment and many other aspects may be different for every new commitment. This fuzzy atmosphere has been repre- sented with the terms ‘uncertainty’ or ‘risk’ by construc- tion managers and researchers, and they tried to control this systematically through risk management and analysis methods since the early 1990s [1]. Some researchers like Flanagan et al. [2] and Pilcher [3] put differentiation between these two terms. They have mentioned that uncertainty represents the situations in which there is no historical data; and risk, in contrast, can be used for situations where success or failure is determined in probabilistic quantities by benefiting from the previous data available. Since such a separation is regarded as meaningless in the construction literature, risk turns out to be the most consistent term to be used for construction projects because some probability values can be attached intuitively and judgmentally to even the most uncertain events [2]. The uncertainty represented quantitatively at some level is not the uncertainty any more; rather it is the risk henceforth and needs to be managed. In this context, this research aims to prove this hypothesis by developing judgmental risk analysis process (JRAP) and applying this process in the assessment of schedule risks of a construction project through a case study. One important way of controlling risks in construc- tion projects is to develop reliable project estimates and schedules [4]. Probabilistic scheduling through conduc- tion of simulations on prepared models provides more powerful results fundamental to making decisions with regard to the control of project risks. Barraza et al. [5] has brought a stochastic approach to traditional S-curve project performance control method by using simulation ARTICLE IN PRESS www.elsevier.com/locate/buildenv 0360-1323/$-see front matter r 2004 Published by Elsevier Ltd. doi:10.1016/j.buildenv.2004.10.013 Ã Corresponding author. E-mail address: aoztas@gantep.edu.tr (A. O ¨ ztas -).