Casting Back Errant Stage in Multi-stage Manufacturing Process

Each stage is influence on product quality in multistage manufacturing process. When product have some problem, the traditional statistical process control method was not detected the exact errant reason timely due to the interaction of each stage. On the basis of the variation transmission model, the conception of virtual stage is proposed. Then, by the hypothesis testing, the stage having errant can be judged exactly. Finally, a knuckle pivot manufacturing process with three stages is given for illustration and verification.