Quantiles

Quantiles for the film thickness are summarized in the following
table.
Quantiles for Film Thickness
100.0%

Maximum

634.00

99.5%


634.00

97.5%


615.10

90.0%


595.00

75.0%

Upper Quartile

582.75

50.0%

Median

562.50

25.0%

Lower Quartile

546.25

10.0%


532.90

2.5%


514.23

0.5%


487.00

0.0%

Minimum

487.00


Capability Analysis

From the above preliminary analysis, it looks reasonable to proceed
with the capability analysis.
The lower specification limit is 460, the upper specification limit is 660,
and the target specification is 560.

Percent Defective

We summarize the percent defective (i.e., the number of items
outside the specification limits) in the following table.
Percentage Outside Specification Limits
Specification

Value

Percent

Actual

Theoretical (% Based On Normal)

Lower Specification Limit

460

Percent Below LSL =
\( 100*\Phi \left( \frac{LSL  \bar{y}}{s} \right) \)

0.0000

0.0025%

Upper Specification Limit

660

Percent Above USL =
\( 100*\Phi \left( \frac{USL  \bar{y}}{s} \right) \)

0.0000

0.0067%

Specification Target

560

Combined Percent Below LSL and Above USL

0.0000

0.0091%

Standard Deviation

25.38468




The value \(\Phi\)
denotes the normal cumulative distribution function, \(\bar{y}\)
the sample mean, and s the sample standard deviation.

Capability Index Statistics

We summarize various capability index statistics in the following table.
Capability Index Statistics
Capability Statistic

Index

Lower CI

Upper CI

CP

1.313

1.172

1.454

CPK

1.273

1.128

1.419

CPM

1.304

1.165

1.442

CPL

1.353

1.218

1.488

CPU

1.273

1.142

1.404


Conclusions

The above capability analysis indicates that the process is
capable and we can proceed with the analysis.
