1. A method comprising: using one or more computer systems, accessing a modeling language representation of a system under test, the representation comprising one or more Message Sequence Charts (MSCs), one or more of the MSCs comprising one or more conditional constructs including at least one or more guards or one or more loops; using the computer systems, generating one or more use scenarios based on the modeling language representation, wherein generating the one or more use scenarios comprises identifying and generating one or more use scenarios for each combination of two MSCs in the order indicated in a directed graph; and using the computer systems, generating one or more validation test suites based on the one or more use scenarios.