Severity: Severity determines the defect's effect on the application. Severity is given by Testers
Priority: Determines the defect urgency of repair.Priority is given by Test lead or project manager
1. High Severity & Low Priority : For example an application which generates some banking related reports weekly, monthly, quarterly & yearly by doing some calculations. If there is a fault while calculating yearly report. This is a high severity fault but low priority because this fault can be fixed in the next release as a change request.
2. High Severity & High Priority : In the above example if there is a fault while calculating weekly report. This is a high severity and high priority fault because this fault will block the functionality of the application immediately within a week. It should be fixed urgently.
3. Low Severity & High Priority : If there is a spelling mistake or content issue on the homepage of a website which has daily hits of lakhs. In this case, though this fault is not affecting the website or other functionalities but considering the status and popularity of the website in the competitive market it is a high priority fault.
4. Low Severity & Low Priority : If there is a spelling mistake on the pages which has very less hits throughout the month on any website. This fault can be considered as low severity and low priority.
Priority is used to organize the work. The field only takes meaning when owner of the bug
P1 Fix in next build
P2 Fix as soon as possible
P3 Fix before next release
P4 Fix it time allow
P5 Unlikely to be fixed
Default priority for new defects is set at P3