Taguchi method is a statistical approach to experimental design aimed at improving product quality. It was developed by Genichi Taguchi to help engineers design robust products and processes. The key aspects of Taguchi's approach include using orthogonal arrays to lay out experiments, incorporating parameter design through setting control factors and levels, and analyzing data using signal-to-noise ratios to identify optimal settings. Taguchi specified three quality characteristics - larger the better, smaller the better, and on-target minimum variation. The document then discusses implementation of Taguchi's method to optimize process parameters for abrasive water jet machining.