Control Charter
Process Improvement
Control limits may be recalculated after a process improvement. Click the button below to recalculate limits, then click the individual points graph at the region where you would like the recalculation to occur.
| Category | Value | New value |
|---|---|---|
| Individuals Upper Control Limit - UCL | 0 | - |
| Individuals Average - Av | 0 | - |
| Individuals Lower Control Limit - LCL | 0 | - |
| Ranges Upper Control Limit - UCL | 0 | - |
| Ranges Average - Av | 0 | - |
Chart Annotation
Add a text label to your Individuals Chart. Type text then enter. It might indicate for example, the cause of a process improvement.
Move the slider to increase the height of the control charts.
Process Capability
These calculations require that you enter specification limits. The Process Capability for this process is currently Cp= and Cpk= . This number is meaningless when the process is out of control. It adds little, if any, value.
Histogram
The histogram can tell a lot about a process, for example whether data has been removed to meet specification. However, selection of a bin width can distort the histogram. The slider below the histogram allows different bin widths to be investigated.
Six Sigma Calculations
Six Sigma's own creator, school teacher and self-confessed con man M Harry, admitted: "Six Sigma is a snow job". Six Sigma should never be used. Six Sigma calculations are nonsense.
Save Your Chart
You can save and load data, or save an image of your chart.
Data is saved and loaded as a csv (comma separated value) file. This is a text file containing two columns separated by commas. If you wish to load 2 columns from Excel, copy the time column then the data column, to a new worksheet before "Save As" csv. Then load the csv into Maxi-Q.
You should use this XmR control charter when you have either single variable data, or count (discrete value) data, at each point in time. Enter your data point and the time it was taken. Tap a point on the chart to read its value. Out-of-control points are highlighted in red. The cause for out-of-control points should be investigated immediately.
Professor Deming's protégé Dr Wheeler, the world's leading proces statistician, has proved that:
You should never use p, np, c, u charts, because they depend on the assumption of a data distribution.
You should never normalize data or check for normality. XmR works for any data distribution.
You should never use detection rules other than points outside control limits, to avoid false alarms.
You should never draw distributions over a histogram because you never know the distribution for a dynamic process.
A control chart (Process Behavior Chart) is an economic chart based on statistics. It is not a probability chart. It does not show a probability of any particular value.
A control chart indicates whether or not a process is predictable. If a process has no points outside control limits, provided it is running within specification, it will continue to give good quality product or service into the future. Points outside control limits indicate the presence of an assignable (special) cause. The special cause may be a shift in the mean or increased variation. This will create an unpredictable process that may result in defects. The process will be incapable of assuring good quality, no matter where specification limits are set. The control chart warns when the process should be investigated.
Every employee has a role in Quality. Q-Skills3D games and interactive exercises teach employees how improve Quality. Q-Skills3D teaches employees how to correctly use and interpret Control charts and histograms.
You may use this software but you cannot copy, or transfer the software to another site. This software is provided on an "as is" basis, without warranties or conditions of any kind, either expressed or implied, including without limitation any implied warranties or conditions of title, fitness for a particular purpose, merchantability or non-infringement.