### Application of Fuzzy Expert Systems to Manage the Projects Time in Iranian Gas Refineries

#### Abstract

The National Iranian Gas Company (NIGC) is one of the top ten gas companies in the gas industry in the Middle East and is comprised of 7 gas refineries. So this company needs to apply the most optimum time management methods to achieve its goals. Custom scheduling calculation of project planning uses the Critical Path Method (CPM) as a tool for Planning Projects activities. CPM is now widely used in planning and managing projects but in spite of its wide application, this method has a critical weak point of not taking into account the uncertainties in scheduling calculation. This article aims to present a precise method based on the application of Fuzzy Expert Systems in order to improve the Time Estimation Method in construction projects and in this regard, reviews the results of the implementation of this method in construction projects of Iranian Gas Refineries. The results show that the proposed method increases the accuracy of time estimation about 7 to 22 percent.

#### Keywords

#### Full Text:

PDF#### References

R. Jain, “Decision-Making in the presence of fuzzy variables”, IEEE Transactions on Systems Man and Cybernetics, Vol. 6, pp. 698-703, 1976

R. Yager, “A procedure for ordering fuzzy subsets of the unit interval”, Information Science, Vol. 24, pp. 143-161, 1981

F. Choobineh, H. Li, “An index for ordering fuzzy numbers”, Fuzzy Sets and Systems, Vol. 5, pp.1-19, 1985

S. L. Liou, M. J. Wang, “Ranking fuzzy numbers with integral value”, Fuzzy Sets, and Systems, Vol. 50, pp 247-255, 1992

P. T. Chang, E. S. Lee, “Ranking of Fuzzy Sets Based on the Concept of Existence”, Computers and Mathematics with Applications, Vol. 27, No 9, pp.1-21, 1994

C. H. Cheng, “A new approach for ranking fuzzy numbers by distance method”, Fuzzy Sets and Systems, Vol. 95, pp. 307-317, 1998

P. A. Raj, A. Kumar, “Ranking alternatives with fuzzy weights using maximizing set and minimizing set”, Fuzzy Sets and Systems, Vol. 105, pp. 365-375, 1999

J. S. Yao, F. T. Lin, “Fuzzy critical path method based on signed distance ranking of fuzzy numbers”, IEEE Transactions on Systems, Man, and Cybernetics-Part A: Systems and Humans, Vol. 30, No 1, pp.76-82, 2000

T. C. Chu, C. T. Tsao, “Ranking fuzzy numbers with an area between the centroid point and the original point”, Computers and Mathematics with Applications, Vol. 43, pp.111-117, 2002.

L. Tran, L. Duckstein, “Comparison of fuzzy numbers using a fuzzy distance measure”, Fuzzy Sets and Systems, Vol. 130, pp. 331-341, 2002

C. Lucas, B. Asady, “A new method for ranking of fuzzy numbers through using distance method”, Journal of Teacher Training University, Vol. 3, pp. 83-88, 2003

S. Abbasbandy, B. Asady “Ranking of fuzzy numbers by sign distance”, Information Sciences, Vol. 176, pp. 2405-2416, 2006

B. Asady, A. Zendehnam, “Ranking fuzzy numbers by distance minimization”, Applied Mathematical Modelling, Vol. 31, pp. 2589-2598, 2007

C. Chen, H. Tang, “Ranking Non-Normal P-Norm Trapezoidal fuzzy numbers with integral value”, Computers and Mathematics with Applications, Vol. 56, pp. 2340-2346, 2008

S. Abbasbandy, T. Hajjari, “A new approach for ranking of trapezoidal fuzzy numbers”, Computers and Mathematics with Applications, Vol. 57, pp. 413-419, 2009

S. Chen, K. Sanguat, “Analyzing fuzzy risk analysis based on a new fuzzy ranking method between generalized fuzzy numbers”, Expert Systems with Applications, Vol. 38, pp. 2163-2171, 2011

P. Rao, N. Ravi Shankar, “Fuzzy critical path analysis based on centroid of centroids of fuzzy numbers and new subtraction method”, International Journal of Mathematics in Operational Research, Vol. 5, No. 2, pp. 205-224, 2013

L. Q. Dat, S. Y Chou, “An Improved Ranking Method for Fuzzy Numbers Based on the Centroid-Index”, International Journal of Fuzzy Systems, Vol. 14, pp. 413-419, 2012

M. Barkhordary Ahmadi, “Ranking of fuzzy numbers based on angle measure”, International Journal of Information, Security and System Management, Vol. 3, No 1, pp. 259-265, 2014

U. A. Sharma, “New lexicographical approach for ranking fuzzy numbers”, Mathematical Theory and Modeling, Vol. 5, No 2, pp. 143-153, 2015

S. Chanas, J. Kamburowski, “The use of fuzzy variables in PERT”, Fuzzy Sets and Systems, Vol. 5, No 1, pp. 11-19, 1981

I, Gazdik, “Fuzzy network planning-FNET”, IEEE Transactions on Reliability, Vol. 32, No 3, pp. 304-313, 1981

S. H. Nasution, “Fuzzy critical path method”, IEEE Transactions on Systems, Man and Cybernetics, Vol. 24, pp. 48-57, 1994

S. Chang, Y. Tsujimura, T. Tazawa, “An efficient approach for large scale project planning based on fuzzy Delphi Method”, Fuzzy Sets and Systems, Vol. 76, pp. 277-288, 1995

P. Lorterapong, O. Moselhi, ”Project-network analysis using fuzzy sets theory”, Journal of Construction Engineering and Management, Vol. 122, pp. 308-318, 1996

J. S. Yao, F. T. Lin, “Fuzzy Critical path Method Based on Signed-Distance Ranking and Statistical Confidence-Interval Estimates”, IEEE Transactions on Systems, Vol. 30, No. 1, pp. 76-82, 2000

S. Chanas, P. Zielinski, “Critical path analysis in the network with fuzzy activity times”, Fuzzy Sets and Systems, Vol. 122, pp. 195-204, 2001

M. Blue, B. Bush, J. Puckett, “Unified approach to fuzzy graph problems”, Fuzzy Sets and Systems, Vol. 125, pp. 355-368, 2002

J. S. Yao, F. T. Lin, “Fuzzy critical path method based on signed distance ranking of fuzzy numbers”, The Journal of supercomputing, Vol. 24, pp. 305-325, 2003

G. S. Liang, T. C. Han, “Fuzzy critical path for project network”, Information and Management Sciences, Vol. 15, No 4, pp. 29-41, 2004

A. Oliveros, A. Robinson, “Fuzzy Logic Approach for Activity Delay Analysis and Schedule Updating”, Journal of Construction and Management, Vol. 131, No. 1, pp. 42-51, 2005

S. Chanas, P. Zielinski, “Critical path analysis in the network with fuzzy activity times”, Fuzzy Sets and Systems, Vol. 122, pp. 195-204, 2006

S. P. Chen, Y. J. Hsueh, “A simple approach to fuzzy critical path analysis in project networks, Applied Mathematical Modelling”, Vol. 32, No. 7, pp. 1289-1297, 2008

S. H. Yakhchali, S. H. Ghodsy Pour, “On latest starting times of activities in networks with imprecise durations and generalized precedence relations”, Applied Mathematical Modelling, Vol. 34, No. 8, pp. 2044-2058, 2010

S. Sathish, K.Ganessan, “A simple approach to fuzzy critical path analysis in project networks”, Journal of Scientific & Engineering Research, Vol. 2, No. 12, pp. 1-6, 2011

P. Rao, N. Ravi Shankar, “Fuzzy critical path analysis based on centroid of centroids of fuzzy numbers and new subtraction method”, International Journal of Mathematics in operational research, Vol. 5, No. 2, pp. 205-244, 2013

S. Elizabet, L. Sujatha, “Project Scheduling Method using Triangular fuzzy numbers and triangular fuzzy numbers”, Applied Mathematical Science, Vol. 9, No. 4, pp. 185-198, 2015

eISSN: 1792-8036 pISSN: 2241-4487