DEK高级培训资料.pdf - 第215页
Your turn…! An archer fi res arrows at a targ et. He perf orms with a stand ard dev iation of 2 cm. The s ize of the targe t (tolerance ) is +/- 25 cm. Calculat e his Sigma, Cp and Cpk Issue 2: July 2007 Sigma = Cp = Cpk…
Cp
Cp =
TOLERANCE RANGE
PATTERN WIDTH
=
TOLERANCE RANGE
=
24
= 2Cp
= 2
= 8
Shifted Process Capability (Cpk)
Issue 2: July 2007
=
TOLERANCE RANGE
6 x stdev
=
24
12
= 2Cp
12
-12 0
Dist. from Mean to nearest Limit
3 X Stdev
Cpk =
=
4_
6
= 0.66 Cpk
Cpk
Your turn…!
An archer fires arrows at a target. He performs
with a standard deviation of 2 cm. The size of
the target (tolerance) is +/- 25 cm. Calculate his
Sigma, Cp and Cpk
Issue 2: July 2007
Sigma =
Cp =
Cpk =
25/2 = 12.5
50/12 = 4.17
25/6 = 4.17
50cm
Your turn…again!
A different archer also has a standard deviation
of 2 cm.
However he fires with an offset of 7 cm !
Calculate his Sigma, Cp and Cpk
Issue 2: July 2007
Sigma =
Cp =
Cpk =
25/2 = 12.5
Unchanged
Unchanged
Lower
50/12 = 4.17
18/6 = 3