What is prioritization in the context of testing?

Prioritization in testing is the process of determining the sequence of test execution and identifying the most critical defects. It helps focus efforts on the most important aspects of the application, ensuring efficiency and timeliness of testing under limited resources.

Prioritization applies to:

• Test cases: Determining which test cases should be executed first (e.g., basic functionality tests, critical business processes).
• Defects: Determining which defects require immediate fixing (directly related to severity and impact on the user).

Key factors influencing prioritization:

• Severity: How much a failure in a function or defect affects the user and business.
• Usage frequency: How often a feature is used or affected by a defect.
• Visibility: How noticeable the defect or problem is to users.
• Risk: The likelihood of error occurrence and its potential consequences.
• Dependencies: The influence of one functionality on another.
• Business requirements: Priorities set by stakeholders.

Defect prioritization systems often use scales, for example:

Priority	Description
High	The defect blocks core functionality, makes the application unusable, or has serious business consequences.
Medium	The defect affects secondary functionality or causes inconvenience but does not block operation.
Low	The defect is cosmetic, related to minor improvements or rare scenarios.

Test case prioritization can be based on the same factors as defect prioritization, as well as on execution order (e.g., smoke > sanity > regression).

Example of defect prioritization in a bug tracker:

// Language-agnostic
// Defect: User cannot log in
// Priority: High
// Severity: Blocking
// Description: When attempting to log in with correct data, the message "Invalid login or password" appears.