Limits tab

On the Limits tab, you can enter specification limits, historical control limits, other limits for the standard. A visual display of these limits helps to ensure that they are entered correctly.

Note: If you do not want to enter a value for any limit or for Target, simply leave the box blank. You should only enter 0 if the limit or target really is 0.

Note: For best results, do not enter values with more decimal places than the Decimal places setting on the General tab (plus one significant digit).
When GainSeeker displays these limits - during data analysis and when editing the SPC standard - they will be rounded to this number of decimal places.
Editing a standard and saving limits that have been rounded to a smaller number of decimal places will save those rounded numbers as the new limits for that standard.

The following information is entered on the Limits tab:

The target value from your blueprint for this characteristic of this part number.

For example, if your print tolerance for a characteristic is 0.75 +/- 0.005, then your target X (nominal) is 0.75.

The upper and lower specification limits from your blueprint for this characteristic of this part number.

For example, if your print tolerance for a characteristic is 0.75 +/- 0.005, then your upper spec is 0.755 and your lower spec is 0.745.

Tip: You can let GainSeeker calculate these limits if they are the same distance from the Target.

  1. Enter the Target value.

  2. Click the -/+ button and enter the tolerance from Target.

  1. When you click OK, GainSeeker will populate the limits:

If you have only one specification limit (also called a one-sided or unilateral tolerance), enter the limit you have and leave the other limit blank. You should only enter 0 if one of your specification limits really is 0, because any specification limit you enter – including 0 – is used to calculate statistics such as Cpk.

Upper and lower limits (other than specification limits) for individual data values within a data subgroup.

The historical control limits for this characteristic. Setting gates is similar to drawing control limits on a paper chart before you begin to collect data.

You only need to set this value if you plan to analyze this standard with the Range/Short Run method of Short Run statistics.

To set the Target R, enter the expected range of measurements for this standard. For example, if measurements on a 2-inch part usually yield 2 inches plus or minus 0.04 inches, then your Target R should be 0.08 inches.

The historical control limits for the ranges for this characteristic. Setting range gates is similar to drawing control limits for the ranges on a paper chart before you begin to collect data.

See the Tip above for letting GainSeeker calculate these limits if they are the same distance from the Target R.

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