2. The following family tree was developed to determine the source of the largest variation for the packaging seal strength operation, in an effort to focus our improvement efforts. Legend: MR = master roll. SR = slit roll Each Master Roll results in 9 Slit Rolls. Each roll is approximately 5000 ft. Hence, when a slit roll is mounted on to the machine, samples are taken from the Top (T), Middle (M) & Bottom (B) of the roll as it is consumed. The machines produces 2 packages simultaneously from Die 1 (D1) and Die 2 (D2).

		T			M			B
MR	SR position	D1	D2		D1	D2		D1	D2
A	1	52	48		52	50		52	50
	5	45	50		54	52		54	54
	9	57	55		55	53		56	52
B	1	54	48		40	45		50	45
	5	50	60		50	53		56	50
	9	58	57		65	63		67	60
C	1	35	38		37	38		35	33
	5	38	42		38	36		35	33
	9	45	41		47	43		45	40

Based on the results above, where should we focus our efforts in order to reduce the seal strength variation?