  Verification is a critical process in the development of engineered systems.
Through verification, engineers gain confidence in the correct functionality of
the system before it is deployed into operation. Traditionally, verification
strategies are fixed at the beginning of the system's development and
verification activities are executed as the development progresses. Such an
approach appears to give inferior results as the selection of the verification
activities does not leverage information gained through the system's
development process. In contrast, a set-based design approach to verification,
where verification activities are dynamically selected as the system's
development progresses, has been shown to provide superior results. However,
its application under realistic engineering scenarios remains unproven due to
the large size of the verification tradespace. In this work, we propose a
parallel tempering approach (PTA) to efficiently explore the verification
tradespace. First, we formulate exploration of the verification tradespace as a
tree search problem. Second, we design a parallel tempering (PT) algorithm by
simulating several replicas of the verification process at different
temperatures to obtain a near-optimal result. Third, We apply the PT algorithm
to all possible verification states to dynamically identify near-optimal
results. The effectiveness of the proposed PTA is evaluated on a partial model
of a notional satellite optical instrument.
