During the concept design of complex networked systems, concept developers
have to assure that the choice of hardware modules and the topology of the
target platform will provide adequate resources to support the needs of the
application. For example, future-generation aerospace systems need to consider
multiple requirements, with many trade-offs, foreseeing rapid technological
change and a long time span for realization and service. For that purpose, we
introduce NetGAP, an automated 3-phase approach to synthesize network
topologies and support the exploration and concept design of networked systems
with multiple requirements including dependability, security, and performance.
NetGAP represents the possible interconnections between hardware modules using
a graph grammar and uses a Monte Carlo Tree Search optimization to generate
candidate topologies from the grammar while aiming to satisfy the requirements.
We apply the proposed approach to the synthetic version of a realistic avionics
application use case and show the merits of the solution to support the
early-stage exploration of alternative candidate topologies. The method is
shown to vividly characterize the topology-related trade-offs between
requirements stemming from security, fault tolerance, timeliness, and the
"cost" of adding new modules or links. Finally, we discuss the flexibility of
using the approach when changes in the application and its requirements occur