The ability to find defects during testing is directly related to the test environment. There is a spectrum of test environments ranging from integrated high-level test environments that give a high-fidelity simulation of the real world to unit test environment that are not close to the real world environment.
High-level blackbox test environments provide the inputs and outputs that are available externally from the component under test. This provides high-fidelity, but does not give the flexibility and granularity to easily control all paths and conditions in...