What's SPC online for?
SPC online are statistical analyses applied to process control data that can provide you with advance notice of out-of-control processes. The SPC methodology implemented in Matics is based on the 8 standard statistical tests that detect different patterns in the sampled process-control data. It's up to you to decide which tests should be used for which parameters, and to configure each test's variables to meet your requirements.
After configuring SPC, you'll be able to automate actions using rules based on the results of these SPC predictions.
Configuring machine parameters for SPC prediction
Go to Online Prediction > SPC Configuration.
Click Configure SPC parameters.
In the expanded department display, select the machine for which you need to configure SPC prediction.
TIP: You can apply the SPC parameter configuration of the currently selected machine to multiple machines before you finish for an efficient configuration workflow.The digest of the machine's parameters, with toggles indicating whether the parameter is sampled or not for SPC prediction, opens on the right.
To sample a parameter that is not yet sampled for SPC, turn the Sample for SPC toggle on.
To change the sampling settings for a parameter that is sampled for SPC, click Edit Settings.
Whether this is a parameter that is newly sampled for SPC, or a parameter that you're updating its SPC configuration, the following settings are offered:
Load Saved SPC Template
If there's an SPC prediction template that already has the statistical tests configured as you want for this parameter, best to load that template as this will automatically configure the parameter's tests: only those tests that are relevant will be active and the set values for each of the selected tests will populate those tests' value boxes.
If there's an existing template that's close to how you want to configure this parameter, you can load it and make adjustments. You can then save it as a new SPC template for reuse.
Finally, if there are templates in the list of templates that are no longer relevant for your site, you can remove them by clicking the delete control and this will tidy up that list.
Tests Settings
Select the check box of the SPC tests to run continuously on this machine parameter.
For each of the selected tests set the test's value. For example, how many consecutive points in the trend test of "
[n] points steadily increasing or decreasing in a row".(optional) Click Save as SPC Template to save the parameter SPC testing configurations for reuse.
Process Limits By X STD - set the number (n) of standard deviations. This value determines the scope of sampled process control data. The upper control limit = avg + (n) * SD. The lower limit = avg - (n) *SD.
The last X sampling points- set how many sampling points of the parameter to include in the calculations of the statistics (mean, standard deviation, upper and lower control limits). This determines the processes' stability outcome.
(optional) Click Apply To.. to apply this parameter's SPC settings to additional machines in which this parameter is in use.
Click Save settings.
When you've finished configuring all the parameters you want to use in SPC prediction for this machine, click Next Machine and repeat from step 6.
If there's just this single machine, that's it.
To remove a machine from your SPC prediction configuration, turn off the
Sample for SPC toggle for all the machine's parameters.
Automating actions based on SPC prediction
Transforming SPC predictive analysis to actions is done through rules.
Click Create new rule to add SPC prediction rules. See rules based on SPC prediction for step-by-step instructions. These rules will be presented in the SPC prediction rules management panel, from which you can edit the rule, delete it or duplicate it to facilitate reuse in slightly modified contexts.
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