Integrated fuzzy AHP and fuzzy TOPSIS methods for multi-objective optimization of electro discharge machining process

In the present work, the working of an electro discharge machining process was studied in which four factors, namely pulse on time, duty cycle, discharge current, and gap voltage, were considered to be the controllable parameters, each at three levels, for monitoring three responses, namely material removal rate, tool wear ratio, and tool overcut. Statistical design of experiments using Taguchi’s orthogonal array (OA) technique has been utilized to determine the optimum level of process parameters so that they are least affected by noise factors for obtaining a robust design of the parameters. Acknowledging the limitation that Taguchi’s OA technique can determine optimal setting of controllable parameters for one output or response at a time, integrated fuzzy AHP and fuzzy TOPSIS methods were used in the scheme of multi-response experiment so that Taguchi’s OA technique may be applied successfully for parametric optimization. The results show that none of the factors were highly significant although discharge current had the highest contribution (31.63%) among all.