Soundness and completeness are two sides of the same coin, used in program analysis to balance between catching all errors and avoiding false positives. Testing-based formal verification has been proposed to reduce test costs and improve software reliability by automatically ensuring the correctness of a program execution path with regard to the functional scenario form of a specification. In this paper, we propose the notions of functional soundness and functional completeness with regard to a functional scenario and develop the corresponding analysis techniques by integrating testing-based formal verification with program slicing. Moreover, we implement tool support for the Java language and conduct an experiment.