Quality Window performs over 50 separate statisical calculations on your data, and displays the results
in the Statistics Box of the individual Quality Window screens.
| Statistic |
Abbrev. |
Explanation |
| Number of Points |
N |
The number of non-null values found in the data selected. |
| Target Deviation |
T-Dev |
The separation between the average and the Target
value of the variable. |
| Standard Deviation - Population |
S-pop |
The square root of the average of the squared distances of the observations from the mean. |
| Current Standard Deviation |
C-SD |
The square root of the average of the squared distances of the observations from the mean based on the current Limit Method. |
| Standard Deviation - Low |
SD-low |
The lowest segmented SD over a given range of data values. |
| Standard Deviation - Moving Range |
SD-mr |
((Moving Range Average * 3.267) - Moving Range Average)/3 |
| Maximum |
Max |
The greatest value of the selected data.
This value will highlight if the maximum value exceeds the specification limits for the variable. |
| Upper Specification Limit |
USL |
Average of all data points plus +4 X the selected SD method |
| Upper Process Capability Limit |
UPCL |
Average of all data points plus +3 X the selected SD method |
| Upper Warning Limit |
UWL |
Average of all data points plus +1.5 X the selected SD method |
| Average |
AVG |
The mathematical average of all data points selected. |
| Current Average |
C-AVG |
The mathematical average of all data points selected based on the current Limit Method. |
| Lower Warning Limit |
LWL |
Average of all data points less -1.5 X the selected SD method |
| Lower Process Capability Limit |
LPCL |
Average of all data points less -3 X the selected SD method |
| Lower Specification Limit |
LSL |
Average of all data points less -4 X the selected SD method |
| Minimum |
Min |
The lowest value of the selected data.
This value will highlight if the maximum value exceeds the specification limits for the variable. |
| Median |
Med |
The middle value of the data set, once numerically sorted. |
| Obs % OSL |
O % OSL |
The percentage of points outside of fixed spec limits. |
| Obs ppm OSL |
O ppm OSL |
The number of points outside of fixed spec limits, expressed in parts per million. |
| Calc % OSL |
C % OSL |
The percentage of points outside of +/- 4SD under the normal curve. |
| Calc ppm OSL |
C ppm OSL |
The number of points outside of +/- 4SD under the normal curve, expressed in parts per million. |
| Variation |
Cr |
The capability ratio describes the size of the process variability relative to the size of the specification range. |
| Targeting |
Tz |
This is determined by dividing the standard deviation into the Target Deviation. This produces a number that measures how well the process is centered on target in standard deviations. |
| Clearance |
Cpk |
Capability Clearance describes the clearance between the process distribution curve and the specification limits in terms of standard deviation. |
| Coefficient Variation |
%CV |
SD divided by average - used to normalize SD so it can be compared to other variables. |
| Moving Range Average |
MR-AVG |
Average of range between all data points. |
| Moving Range UCL |
MR-UCL |
+3 X Moving Range Standard Deviation |
| Moving Range UWL |
MR-UWL |
+1.5 X Moving Range Standard Deviation |
| Moving Range LWL |
MR-LWL |
-1.5 X Moving Range Standard Deviation |
| Rule Violation |
Rule |
Alarms based on limits or consecutive data points. |
| Sum |
Sum |
The total of all data points for a variable. |
| Last Value |
LV |
The last non-null value for the currently selected variable. |
