Severity ratings for usability reviews

A quick reminder of severity ratings – these ones are adapted from ‘Usability severity codes’ in Usability & Technical Documentation, Xerox Corporation, July 1995.

One point to remember – if you are developing applications for internal use in an organisation, you can often downgrade the severity of issues as there is no competition if users get annoyed – they are forced to use the application. Instead you should probably focus on issues that are causing productivity losses that hit the bottom line.

1 – Critical

An emergency condition that causes the customer’s system to fail or causes customer data to be lost or destroyed. A showstopper usability bug can also be one that is likely to cause frequent data integrity errors. There is no workaround to these problems. A key feature needed by many customers is not in the system.

2 – High

A serious condition that impairs the operation, or continued operation, of one or more product functions and cannot be easily circumvented or avoided. The software does not prevent the user from making a serious mistake. The usability problem is frequent, persistent, and affects many users. There is a serious violation of standards.

3 – Medium

A non-critical, limited problem (no data lost or system failure). It does not hinder operation and can be temporarily circumvented or avoided. The problem causes users moderate confusion or irritation.

4- Low

Non-critical problems or general questions about the product. There are minor inconsistencies that cause hesitation or small aesthetic issues like labels and fields that are not aligned properly.