Comparison of Phase 2 Results

The four GP models provided different optimal solutions and goal achievements. In order to compare the four solutions and their trade-offs, we use the value path approach (VPA) discussed in Ghapter 6, Section 6.4.9. VPA is one of the most efficient ways to demonstrate the trade-offs among conflicting criteria. The display consists of a set of parallel scales, one for each criterion, on which is drawn the value path for each optimal solution. 

The value assigned to each optimal solution on a particular axis is the ratio of that solution s value for the appropriate objective to the best value obtained for that objective. Since we are minimizing all the four objectives, the minimum value for each axis is 1 and all the ratios are greater than or equal to 1. 

To present these results to the DMs, the following steps are used in VPA. First, the best solution achieved for each objective is found. For the price objective, non-preemptive GP has the best value of 518,330 (see Table 7.26) for lead time, preemptive GP is best with a value of 10.516 for MtT the best value of 13,098,580 is obtained through preemptive GP and for the VaR, the best value 

Comparison of phase 2 results by value path approach. 

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