Process templates can be also deleted but there is some certain restrictions with regard to inbuilt or the default templates that exist in Azure DevOps
- Default Process templates like Basic,Agile,Scrum and CMMI can be never deleted
- Inherited Process templates based on Basic,Agile etc., can be deleted if the user has Organizational Admin access
- Imported Process templates from TFS/Azure DevOps can be also deleted
But before deleting Process templates make sure that you don’t have any projects, otherwise Azure DevOps will display an error message