The purpose of this paper is to develop 7 wt% yttria stabilized zirconia (7YSZ) thermal barrier coatings by optimization of the atmospheric plasma spraying process parameters. Multiple-performance characteristics, such as coating thickness and surface roughness were considered for optimization. Eighteen experimental runs based on the L₁₈ orthogonal arrays of the Taguchi method were used to show the best conditions among the plasma spraying parameters. Thereafter, best possible process parameters were obtained by the analysis of variance using grey relational analysis as the quality guide. Results signify the application possibility of the grey-based Taguchi technique for continuous development of quality coating in the area of advanced manufacturing technology.