Modified condition/decision coverage

MC/DC or Modified Condition/Decision Coverage, is used in the standard DO-178B to ensure that Level A (Catastrophic) software is tested adequately.

It is a form of exhaustive testing, in that during testing all of the below must be true at least once:

• Each decision tries every possible outcome
• Each condition in a decision takes on every possible outcome
• Each entry and exit point is invoked
• Each condition in a decision is shown to independently affect the outcome of the decision

Independence of a condition is shown by proving that only one condition changes at a time.