We are moving to an industry best practice of severities. The following is a suggested mapping to help you select the right one:
PrioritySeverity P0Sev 1 P1/P2Sev 2 P3Sev 3 P4Sev 4
Level 1 – Critical: Critical production issue affecting all users, including system unavailability and data integrity issues with no workaround available.
Level 2 – Urgent: Major functionality is impacted or significant performance degradation is experienced. Issue is persistent and affects many users and/or major functionality. No reasonable workaround available. Also includes time-sensitive requests such as requests for feature activation or a data export.
Level 3 – High: System performance issue or bug affecting some but not all users. Short-term workaround is available, but not scalable.
Level 4 – Medium: Inquiry regarding a routine technical issue; information requested on application capabilities, navigation, installation or configuration; bug affecting a small number of users.