CriticalHighMediumLow

CriticalHighMediumLow is a four-tier framework used to classify issues, incidents, vulnerabilities, and tasks by their impact and urgency. It is widely used in information technology, software development, cybersecurity, and risk management to guide triage and resource allocation. While not a universal formal standard, the four levels provide a compact shorthand that teams can apply across disciplines.

The levels are typically defined as Critical, High, Medium, and Low. Critical issues cause complete outages, severe data loss, or other conditions that threaten essential operations and usually require immediate escalation and rapid remediation. High issues affect major functionality or a large number of users but do not halt operations. Medium issues have noticeable impact on performance or usability, with remediation planned on a shorter timeline. Low issues are minor defects, cosmetic problems, or enhancement requests with minimal risk.

Definitions and SLAs vary by organization, and some teams pair the scale with color codes or separate severity and priority fields. Common practice is to establish objective criteria and documented thresholds for each level to reduce subjective judgments and ensure consistent responses.

Using CriticalHighMediumLow supports prioritization, backlog management, and service-level commitments by communicating urgency clearly to stakeholders. It is commonly seen in bug trackers, incident response playbooks, and risk assessments, though the exact meaning of each level should be explicitly defined within a given context.