If you are having the access rights of workitem configuration, then you will able to add/remove workitem severity.
To configure workitem,
1. Click on Admin on right-hand side of the header.
2. Select Company Admin.
3. Click on Workitem Configuration.
Add Workitem Severity
To add a workitem severity,
1. Click on Add Severity.
2. Give an appropriate name.
3. Select a system-generated icon.
4. Click on Save.
Edit Workitem Severity
To edit severity,
1. Click on severity Name of the severity you want to edit.
2. By clicking outside the edit box would save automatically.
Archive Workitem Severity
To Archive severity,
1. Click on Delete icon.
2. Clicking on confirmation would open pop up of Archive.
To restore severity again,
1. Click on Archive Button.
2. Click on Restore icon next to the severity you want to restore.
3. Click on confirmation to Restore.