Issue 20

P. Rezakhani, Frattura ed Integrità Strutturale, 20 (2012) 17-21; DOI: 10.3221/IGF-ESIS.20.02 20 probability and the risk severity with which a project are assessed. in linguistic terms and to convert them into corresponding fuzzy numbers. Second step, Definition of fuzzy inference, is to define the relations between input parameters and output parameters in “if-then” rules or mathematical functions using an appropriate fuzzy arithmetic operator. Final step, Defuzzification, is to convert the fuzzy result into an exact numerical value. These and other researchers recommend taking into account the imprecise, vagueness, and fuzziness of the risk factors in a construction project to appropriately deal with a contractor’s project risks by using Fuzzy Set Theory (FST). It is well accepted that Fuzzy Set Theory (FST) provides a useful way to deal with ill-defined and complex problems in a decision making by quantifying imprecise information, incorporating vagueness, and making decisions based on the imprecise and vague data. The method allows translating the subjective judgment given in linguistic expressions (i.e., “low”, “high” etc) into mathematical measures. Dikmen et al. [42] mentions that FST is commendable to project-based industries because it is almost impossible to use probabilistic methods due to the unique nature of construction undertakings. The rational to use FST in project risk assessment are as follows; first, the modeling of vague input is successfully done with the use of membership functions. Second, the inherent ability of FST to explain its reasoning ensures that the modeling process is understood and could also be intuitively verified. Third, the parallel nature in which rules are activated in a fuzzy system ensures that all factors are considered in a harmonized manner. Fourth, the results of fuzzy systems can naturally be scaled to be comparable with each other, with the use of the scaling membership functions. Finally, Fuzzy logic’s use of linguistic sets and rules ensures that the terminology of the user interface and modeling structure can be tailored toward the specific environments. R EFERENCES [1] W. Mark, P. E. Cohen, R. P. Glen, Project Risk Identification and Management. AACE International Transaction. INT.01.1-5.S (2004). [2] E. Chia, Risk assessment framework for project management. IEEE, (2006) 376. [3] Karimiazari et al., Expert Systems with Applications, 38 (2011) 9105. [4] T. Zayed, M. Amer, J. Pan, International Journal of Project Management, 26 (4) (2008) 408. [5] D. Hillson, Effective opportunity management for projects – exploiting positive risk. New York: Marcel Dekker (2004) [6] R. Olsson, International Journal of Project Management, 25 (2007) 745. [7] H. Douglas,. The failure of risk management: Why it`s broken and how to fix it. John Wiley and sons, (2009) 46. [8] Tuysuz, Kahreman, International Journal of Intelligent Systems, 21 (2006) 559. [9] P. L. Bannerman, The Journal of Systems and Software, 81(12) (2008) 2118. [10] P. Elkington, C. Smallman, International Journal of Project Management, 20 (2002) 49. [11] C. Chapman, International Journal of Project Management, 15 (1997) 273. [12] Risk Analysis and Management for Projects (RAMP). Institution of Civil Engineers and Faculty and Institute of Actuaries. Thomas Telford, London (2002). [13] Project Management Institute,. A guide to the project management body of knowledge. Project Management Institute Standards Committee (2008). [14] Institute of Risk Management,. A risk management. Standard Institute of Risk Management (2002). [15] A. Nieto-Morote, F. Ruz-Vila, International Journal of Project Management, 29 (2011) 220. [16] D. F. Cooper, C. B. Champan, Risk Analysis for Large Project.Wiley, Chichester (1987). [17] P. J. Edwards, P. A. Bowen, Engineering, Construction and Architectural Management, 5(4) (1998) 339. [18] A. Klemetti, Risk management in construction project networks. Report 2006/ 2. Finland: Laboratory of Industrial Management, Helsinki University of Technology (2006). [19] L. Zhou, A. Vasconcelos, M. Numes, Information Management & Computer Security, 16 (2008) 166. [20] J. H. M. Tah, A. Thorpe, R. McCaffer, Computing System in Engineering, 4 (1993) 281. [21] E. N. Wirba, J. H. M.Tah, R. Howes, Journal of Engineering, Construction and Architectural Management, 3 (1996) 251. [22] J. C. Bennett, G. A. Bohoris, E. M. Aspinwall, R.C. Hall, European journal of operation research, 95 (1996) 467. [23] D. White, Management Decision, 3(10) (1995) 35. [24] A. Kaufmann, M. M. Gupta, Fuzzy mathematical models in engineering and management science. Amsterdam: North-Holland (1988). [25] T. Terano, K. Asai, M. Sugeno, Fuzzy systems theory and its applications. San Diego, CA: Academic Press (1992).