The software testing, in addition to structural measures (for example, work on the software development processes, methods and the use of tools), is an essential part of software quality assurance. Mostly one distinguishes - as well as the IEC 62304 - the following test levels:

• Unit, component or class tests
• Software integration testing
• Software system testing
• Software validation (in stand-alone software)

There are other measures of the analytical quality assurance of software that are not software testing. They includes the verification of the source code of software. For example, that determine, by code reviews or by tools, code metrics, bug patterns, etc..

Software testing and IEC 62304

The IEC 62304 does not require (!) software testing in software safety class A. For safety classes B and C all test levels are required.