  As simulation is increasingly used in scenario-based approaches to test
Automated Driving Systems, the credibility of simulation results is a major
concern. Arguably, credibility depends on the validity of the simulation setup
and simulation models. When selecting appropriate simulation models, a
trade-off must be made between validity, often connected to the model's
fidelity, and cost of computation. However, due to the large number of test
cases, expert-based methods to create sufficiently valid simulation setups seem
infeasible. We propose using design contracts in order to semi-automatically
compose simulation setups for given test cases from simulation models and to
derive requirements for the simulation models, supporting separation of
concerns between simulation model developers and users. Simulation model
contracts represent their validity domains by capturing a validity guarantee
and the associated operating conditions in an assumption. We then require the
composition of the simulation model contracts to refine a test case contract.
The latter contract captures the operating conditions of the test case in its
assumption and validity requirements in its guarantee. Based on this idea, we
present a framework that supports the compositional configuration of simulation
setups based on the contracts and a method to derive runtime monitors for these
simulation setups.
