But end users don’t care about this – if they have an IT issue their perceived priority is usually “high.” A priority matrix is a useful tool in IT service management (ITSM) which lets service desk agents assign a priority to an incident ticket based on the impact and urgency. ITIL defines incident priority as impact X urgency, which means that the priority of an incident ticket is determined by the effect it has on business and the time available for repair (or avoidance) before the incident’s impact is felt by the business.