Testbarkeit ist der Grad, zu dem ein Softwareprodukt das Testen (in einem bestimmten Testkontext) ermöglicht.

Weitere Defintionen:

• The relative ease and expense of revealing software faults. [Bind94]
• (1) The degree to which a system or component facilitates the establishment of test criteria and the performance of tests to determine whether those criteria have been met, and
  (2) the degree to which a requirement is stated in terms that permit establishment of test criteria and performance of tests to determine whether those criteria have been met. [IEEE90]
• A set of attributes that bear on the effort needed for validating the modified software. [ISO9126]
• A software system is testable if 1) its components can be tested separately, 2) test cases can be identified in a systematic manner and repeated, and 3) the test results can be observed. [Kahl98]

Die Testbarkeit wird durch eine Vielzahl von Faktoren bestimmt. Faktoren