Question: Hose Skiving. Siegler, Heches, Hoppenworth, and Wilson applied the six-step process-oriented quality assurance cycle to a skiving operation. Skiving consists of taking rubber off the ends of steel-reinforced hydraulic hose so that couplings may be placed on these ends. A crimping machine tightens the couplings onto the hose. If the skived length or diameter are not as designed, the crimping process can produce an unacceptable finished hose.
(a) What two variables did the investigators identify as directly related to product quality?
(b) Which step in the six-step cycle was probably associated with identifying these two variables as important?
(c) The analysts applied steps 3 and 4 of the six-step cycle and found that for a particular production line, aim and variation in skive length were satisfactory. (Unfortunately, outside diameter data were not available, so study of the outside diameter variable was not possible.) In keeping with the doctrine of continual improvement, steps 5 and 6 were considered. Was this a good idea? Why or why not?