On a project record, click Actions | Project Versioning | Create Version. The Create Version window opens. Using Classic: On the project page or the Managed Versions related list, click New Project Version. The Create Version page opens.
Complete the fields, as needed. Version Name is the only mandatory field. The fields are described in Create Project Version Fields.
You can have only one project version as your baseline, and you cannot delete project baseline versions. To change the baseline status for a version, either:
Create another version, as above, and select the Baseline checkbox. This version replaces the previous version as the baseline.
Edit the existing baseline version and deselect the Baseline checkbox.