Page 418 - The Handbook for Quality Management a Complete Guide to Operational Excellence

np Chart p Chart
LCL = np − 3 np 1 − p) LCL = p − 3 p 1 − p)
(
(
LCL n
Or 0 if LCL is negative Or 0 if LCL is negative
Center Line np = sum of subgroup defective counts p = sum of subgroup defective counts
b
sum of subgroup sizes
f
number of subgroups
UCL = np + 3 np 1 − p) UCL = p + 3 p 1 − p)
(
(
UCL n
or n if UCL is greater than n or 1 if UCL is greater than 1
c Chart u Chart

LCL = c − 3 c LCL = u − 3 u
LCL n
Or 0 if LCL is negative Or 0 if LCL is negative
Center Line c = sum of subgroup occurrences u = number of units in all subgroups
sum of subgroup occurrences
s
number of subgroups
r
UCL UCL = c + 3 c UCL = u + 3 u n

X Chart
LCL LCL = X − 2 66 × R
.
Center Line X = number of measurements
sum of measurements

.
UCL UCL = X + 2 66 × R

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