Coverage Based Test-Case Generation Using Model Checkers

This paper presetits a method for automatically generating test cases to structural coverage criteria. We show how a niodel checker can be used to autoniutically generate complete test sequetices that will provide a predefined coverage of uti? soffivare developnietit artifact that can be represented as a ffiriitr state niodel. Our goal is to help reduce the high cost of developitig test cases f o r safep-critical sojfivare applications that require a certain level of coveruge for certijicatioti, f o r example, safep-critical avionics sxstenis that need to denlotistrate MC/DC (modijied cotidition arid decision) coverage of the code. We deftie aJmiial franiework suitable for modeling soft\care artifacts, like, reqitirenients models, software spec$cations, or inipletnetitatiotis. We then show how various structural coverage criteria can be formalized and used to make a triode1 checker provide test sequences to achieve this coverqe. To illustrate our approach, we demonstrate, for the first titiie, how a niodel checker can be used to generate test sequerice.sfor MUDC coverage of a m a l l case example.