This thesis developed three defuzzification approaches to convert the coefficients and the variables of the fuzzy linear programming problems (FLPP) into crisp (deterministic) linear programming problems (CLPP) and obtain the critical path with the optimal completion time for the different fuzzy network problems.The three defuzzification approaches are based respectively on the philosophies of probability density function, ranking measures and the program evaluation and review technique (PERT).Finally, the critical path method (CPM) has been used to compare its results with our obtained results to give more credit to our approaches.The case study is considered from a real problem to verify our results that obtained using “Matlab2010R” software.
