In: Operations Management
A quality control inspector has taken four samples with five
observations each at the Beautiful Shampoo Company, measuring the
volume of shampoo per bottle. If the average range for the four
samples is 0.4 ounces and the average mean of the observations is
20.0 ounces, develop 3-sigma control limits for the bottling
operation. (Round answers to
2 decimal places, e.g. 15.25.)
CL | ||
UCL | ||
LCL |
3 Sigma control limits for example :
must be created for Xbar graph and Range outline
Given ,
Xbar = Average mean of perceptions = 20 ounce
Rbar = Average Range of perceptions = 0.4 ounce
Control Limits for Xbar graph :
Given an incentive for A2( for test size = 5) as got from standard table for control graph constants is = 0.577
Upper Control Limit = UCL = Xbar + A2.Rbar
= 20 + 0.577 x 0.4
= 20 + 0.2308 = 20.2308 Ounce
((23 .28 adjusted to 2 decimal spots)
Lower Control Limit = LCL = Xbar – A2.Rbar
= 20 - 0.577 x 0.4
= 20 – 0.2308= 19.7692 Ounce ( 19.77 adjusted to 2 decimal spots)
Focus line = Xbar = 20 Ounce
Control outline for Range graph :
Following are the given estimations of D3, D4 got from standard table for control outline constants for
test size = n = 5:
D3 = 0
D4 = 2.114
Lower Control Limit = LCL = D3 X Rbar
= 0 x 0.4
= 0 Ounce
Upper Control Limit = UCL = D4 X Rbar
= 2.114 x 0.4
= 0.8456
( 0.85 adjusting to 2 decimal spots)