Coverage Based Test-Data Generation using Model Checkers

Abstract

We present a method for automatically generating test cases that satisfy certain structural coverage criteria. We show how a model checker can be used to automatically generate complete test sequences that provide a predefined coverage of any software development artifact, given a finite state model of the artifact. Our goal is to help reduce the high cost of developing test cases for safety-critical software applications that require a certain level of coverage for certification, for example, safety-critical avionics systems that need to demonstrate MC/DC (modified condition and decision) coverage of the code.

We define a formal framework suitable for modeling various software artifacts, for example, requirements models, software specifications, or implementations. We then demonstrate how various structural coverage criteria can be formalized and used to make a model checker provide test sequences to achieve this coverage. To illustrate our approach, we demonstrate, for the first time, how a model checker can be used to generate test sequences for MC/DC coverage of a small case example.