Application of Taguchi Methods to Expedite a Diecasting Launch

The Ford E40D transmission is a new design for which Doehler Jarvis will diecast aluminum cases. Peproduction process development ranged from baseline evaluation to Taguchi parameter design. An improved process was predicted from which confirmation tests showed improved dimensional Cp ratios of 1.6-2 with porosity rejects reduced to only 0.3%. A Loss Function savings of $36.24 (77%) per unit was calculated due to reduced porosity. Production began 11/11/88 with a run of 700 pieces at a First Time Capability of 92%. Pre-Taguchi baseline FTC in April 1987 was 60%.