A Trade-off Ranking Method: Case of Extreme Solutions Redundancy

In the trade-off ranking (TOR) method, the determination of the extreme solution (ES) is the main step before ranking the alternatives. ES reflects the best value of one criterion in a conflicting multi-criteria problem. However, the redundancy in selecting the ESs occurs because of the redundancy in some of the criteria values. Based on the stated problem, an improved TOR method is introduced in this paper to cater the redundant ES problem. An example is used from the literature to test the improvisation. The result indicates the implementation of the TOR method provides a better solution since it satisfies two conditions which are the highest value for different weights and the least compromise values in average weights. This verifies the reasonableness and effectiveness of the TOR method.