Bebugging is a way to improve the quality of the product by introducing a new known defect. It is also used in determining the reliability of test set/test suite. It is achieved NOT by developing more tests but by introducing new defects.
Run Time Injections technique uses a trigger to inject a fault into a software system dynamically using a number of ways such as Time based triggers and Interrupt-based triggers. There are various tools and techniques that are used to insert fault into the system manually or during run time.
Some of the commercial Fault Injection tools are listed below :
The Mu Service Analyzer