You are currently designing the TAA of a TAS. In particular, you have been asked to adopt an approach for automatically generating and executing test cases from a model that defines the SUT. The SUT is a state-based and event-driven system that is described by a finite-state machine and exposes its functionality via an API. Assume also that the behavior of the SUT depends on possibly unreliable hardware or communication links.

Based only on the given information, which of the following aspects would you expect to be most important when designing the TAA in this scenario?