The multi-vari chart shows you variation by separating it into three possible sources (within-piece, piece-to-piece, and time-to-time.)
Other Designed Experiment Types include one-factor designs like randomized block plans, Latin square designs, and Garaceo-Latin designs.
Design for Excellence (aka Design for X, DFX) is a systematic approach for designing where X is the objective for the product or process
FMEA (Failure Mode Effects Analysis) is a tool that helps us anticipate what might go wrong with a process and identify the possible causes.
Taguchi Robust Design is a function of product design. Robust products have a strong signal-to-noise ratio.