Uppaal

UPPAAL is a tool suite for modeling, simulation, and verification of real-time systems. It is based on timed automata, a formalism for specifying systems in which timing constraints are essential. UPPAAL supports networks of interacting timed automata with clocks, guards, invariants, and synchronization on channels, enabling precise specification of timing behavior. The aim is to assist researchers, engineers, and students in modeling, analyzing, and validating real-time designs.

The system provides a graphical model editor, a simulator, and a model checker. Models are built from templates that represent timed automata with locations, transitions guarded by clock constraints, and data variables. Transitions may synchronize on binary channels, and the tool supports urgent and committed locations to express specific timing semantics. Models can include declarations, processes, and parameters to capture complex real-time systems.

Verification is performed via symbolic state-space exploration, using difference-bound matrices to represent clock constraints. Properties are written in the UPPAAL query language, a temporal-logic subset used to express reachability, safety, liveness, and timing requirements (for example, A[] p, E<> p). UPPAAL reports whether a property holds and can provide diagnostic traces illustrating how a property is violated.

In addition to the core capabilities, UPPAAL SMC offers statistical model checking for stochastic timed automata, enabling performance and reliability assessments under probabilistic assumptions. The suite is widely used in academia and industry to model embedded controllers, real-time communication protocols, and robotic systems. It originated from a collaboration between Uppsala University and Aalborg University and has become a standard reference in real-time verification. UPPAAL is distributed with an academic license and additional commercial licenses.