Designing, animating, and verifying partial UML Models

Models have been shown to be useful during virtually all stages of the software lifecycle. They can be reverse engineered from existing artifacts, or created as part of a system's execution, but in many cases models are created by designers from informal specifications. In the latter case, such design models are typically used as means of communication between designers, and developers. They can also in some cases be validated by simulation over test cases, or even by formal verification. However, most existing model simulation or verification approaches require relatively consistent and complete models, whereas design models often start small, incomplete, and inconsistent. Moreover, few design models actually reach the stage where they can be simulated, and even fewer the stage where they can be formally verified. In order to address this issue, we propose a partial modeling approach that makes it possible to animate incomplete and inconsistent models. This approach makes it possible to incrementally improve testable models, and can also help designers reach the stage where their models can be formally verified. A proof-of-concept tool called AnimUML has been created in order to provide means to evaluate the approach on several examples. They are all executable, and some can even undergo model-checking.