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.

Upper and lower limits for each data subgroup. This is often used to record and display historical control limits for this characteristic - similar to drawing control limits on a paper chart before you begin to collect data.

Entering Gate limits does not affect how GainSeeker calculates and reports Control Limits throughout the system. If you need to configure GainSeeker to use historical control limits instead of calculated control limits, see Using Gate limits for Historical Control limits.

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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