This feature is available in Ultimate edition only.
You can create regression plans to define coordinated sets of testing activities to ensure that existing functionality works as designed. Note that a regression plan can contain multiple regression suites.
Go to Release Planning > Regression Planning.
Click New Plan to open the Regression Plan window.
At the top, enter a title, then assign your plan to a project by selecting it from the Project drop-down list. Optionally, you can enter a detailed description, assign an Owner, and include Reference data.
Click Save. The system adds your new regression plan to the list of plan types on the left, and assigns it a unique ID (RP-nnnnn).