  Increased complexity in cyber-physical systems calls for modular system
design methodologies that guarantee correct and reliable behavior, both in
normal operations and in the presence of failures. This paper aims to extend
the contract-based design approach using a directive-response architecture to
enable reactivity to failure scenarios. The architecture is demonstrated on a
modular automated valet parking (AVP) system. The contracts for the different
components in the AVP system are explicitly defined, implemented, and validated
against a Python implementation.
