This blog has a link to a sample Crystal Report which contains an SPC process control chart.
You can set the upper and lower thresholds (the grey lines shown in the chart) to constant values or to a database field which will then determine the outlying values.
This sample has instructions (on the design tab of the report itself) on setting the report to your own data environment. The report also has sample data so you can see if it can be useful for your business.
If you have an existing report (i.e. you are not building a brand new report) and you wish to have a process control chart in that report, you can insert this sample as a sub-report. Use the Insert menu > Sub-report option in the Crystal Reports designer after setting the report to your own data-source.
You can use this sample in Crystal Reports version 9 and up. This is considered a beginner to intermediate task. It involves using the Database Expert and changing several formulae.
You can download the sample here.