Priority is calculated based on a matrix of Impact (Effect on organization) and Urgency (Speed of resolution needed) :
P1 – Critical: Severe business impact. A production system is down, or many users are blocked. Immediate attention is required.
P2 – High: Major disruption. The service is degraded or performance is poor, but it is partially available.
P3 – Medium: Moderate issue. Features are not behaving as expected, or a single user is affected. Operations continue.
P4 – Low: Minor impact. Cosmetic issues, "How-to" questions, or general inquiries