Time Series Controls

Specification Limits

This page discusses how to set the specification limits. The specification limits are at both the series level and the limit range (multiple/split limit) level. However, the series level calculations are actually the first limit range calculations. The specification limits are used with the run rules and are based upon the process being examined. The time series controls of the .Net Analytics package include the following:

Individuals (IndChart)
Moving Range (MovRngChart)
Moving Average (MovAvgChart)
Xbar (XbarChart)
Range (RangeChart)
Standard Deviation (StdDevChart)
RMS Deviation (RMSDevChart)

The series classes of the respective charts are:

The specification limits include the following properties:

USL - upper specification limit
NSL - nominal specification limit
LSL - lower specification limit

Set Specification Limits

Below, we will set the specification limits of an Individuals series (named isSeries in the examples below) and the second limit range of the series. You can find out how to add a second limit range (multiple/split limits) here. The process is similar for the other charts:

[Visual Basic]

' Set and show the specification limits of the series - this is actually the first limit 
                  range
isSeries.USLShow = True

                  isSeries.USL = 1.0

                  isSeries.NSLShow = True

                  isSeries.NSL = 0.5

                  isSeries.LSLShow = True

                  isSeries.LSL 
                  = 0.0

                  

                  ' Set and show the specification limits of the second limit range
isSeries.LimitRanges(1).USLShow 
                  = True

                  isSeries.LimitRanges(1).USL = 0.7

                  isSeries.LimitRanges(1).NSLShow = True

                  isSeries.LimitRanges(1).NSL = 0.4

                  isSeries.LimitRanges(1).LSLShow = True

                  isSeries.LimitRanges(1).LSL = 0.1

[Visual C#]

// Set and show the specification limits of the series - this is actually the first limit 
                  range
isSeries.USLShow = true;

                  isSeries.USL = 1.0;

                  isSeries.NSLShow = 
                  true;

                  isSeries.NSL = 0.5;

                  isSeries.LSLShow 
                  = true;

                  isSeries.LSL = 0.0;

                  

                  // Set and show the specification limits of the second limit range
isSeries.LimitRanges[1].USLShow 
                  = true;

                  isSeries.LimitRanges[1].USL = 0.7;

                  isSeries.LimitRanges[1].NSLShow = true;

                  isSeries.LimitRanges[1].NSL = 0.4;

                  isSeries.LimitRanges[1].LSLShow = true;

                  isSeries.LimitRanges[1].LSL = 0.1;

After the series has been added, samples or subgroups may then be added to the series. Adding samples and subgroups is discussed here and here respectively. The resulting chart before and after the specification limits are set should look similar to the following:

Individuals chart with no specification limits

Individuals chart with specification limits