CS447 Lecture 4: L2.pdf
Document Summary
Recall that a fault is something that"s latent or hiding, while a failure is visible (e. g. epic fail). To get from a fault to a failure: fault must be reachable, program state subsequent to reaching fault must be incorrect: infection; and, infected state must propagate to output to cause a visible failure. Applications of the rip model: automatic generation of test data, mutation testing. Informally, a test case contains: what you feed to software; and, what the software should output in response. Here are two de nitions to help evaluate how hard it might be to create test cases. De nition 1 observability is how easy it is to observe the system"s behaviour, e. g. e ects on the environment, hardware and software. its outputs, De nition 2 controlability is how easy it is to provide the system with needed inputs and to get the system into the right state. Consider testing a cellphone from the o state: (cid:104) on (cid:105)
