  Ensuring the safety and efficacy of Cyber-Physical Systems (CPSs) is
challenging due to the large variability of their operating environment. Model
checking has been proposed for validation of CPSs, but the models of the
environment are either too specific to capture the variability of the
environment, or too abstract to provide counter-examples interpretable by
experts in the application domain. Domain-specific solutions to this problem
require expertise in both formal methods and the application domain, which
prevents effective application of model checking in CPSs validation. A
domain-independent framework based on timed-automata is proposed for
abstraction and refinement of environment models during model checking. The
framework maintains an abstraction tree of environment models, which provides
interpretable counter-examples while ensuring coverage of environment
behaviors. With the framework, experts in the application domain can
effectively use model checking without expertise in formal methods.
