All Defects Aren’t Created Equal

Defects can range from critical to cosmetic

Defects or errors or bugs or flaws or failures in an application can be caused because of multiple reasons. Whatever are the reasons and the results organizations should not appraise all defects equally. Even today many enterprises view all the defects in an application in the same vein and sometimes run after fixing the cosmetic defects while forgetting the critical.

The truth be said: some defects have higher impact on the functionality, product or service than others.  

Critical - Functionality, product or service will not run, aborts spontaneously, or is providing or will result in serious information errors or information corruption; it affects the customer. 
 
Major -  Functionality, product or service runs, but major information errors are possible, or a major part of the functionality is unavailable; it may affect the customer. 
 
Minor - Minor information errors are possible, or a minor part of the functionality is unavailable, with no significant impact on the customer.
 
Cosmetic - Minor errors are possible that affect the appearance of a functionality, product or service with hardly any impact on the customer.  

- Source Gartner

While everyone agrees that all defects in an application needs to be found and fixed effort should be allocated based on where it matters most rather, than just based on appearance of a functionality.