Nearly-Optimum Selection Of Strength T Orthogonal Arrays: A Strength and Efficiency Appraisal

The process of enumeration and construction of orthogonal arrays has been extensively studied and several methods to develop and implement them have been proposed. There is, however, a gap in the literature when deciding the most appropriate orthogonal array to be tailored to a specific situation. Romero and Murray [1] presented a combinatorial-based technique to list all the possible isomorphic arrays for a given design type and undertook the enumeration of almost all of them (up to 100 runs). The size of the orbits under consideration (the number of isomorphic arrays or possible arrangements for the same design type) was found very large. Certainly, the decision to select the most suitable array for a given situation becomes a non-trivial and computationally intensive task. Some attempts to overcome this problem have been proposed [2] [3], yet a context-based approach has not fully been taken into consideration. In this paper, an engineering-based approach is presented to select orthogonal arrays according to their isomorphism and experimental implementation. The arrays were simulated and tested using a protective relay and its associated circuits. Although still in the process of testing, preliminary results show important performance advantages over traditional techniques such as crossed arrays, combined arrays and response surface methods.