There are many cases where rerunning of an existing test run may be useful. TestRail includes a quick link for this in the test run toolbar. Following steps should follow while rerunning the test case
Click on Rerun button present at toolbar.
It opens select tests wizard where user can select the test cases based on status of previous result.
After selection, click on OK button.
Following screenshot displays how to rerun test cases
It opens Add Test Run page where user should enter Name, Milestone, Assigned To, Description as shown in below screenshot.
By default 2nd option is selected.
User can see number of test cases included and click on Add Run button as following screenshot
Now user can see pie-chart and test cases into Test Runs & Results tab as following