A sequential operation system component (e.g., shell) testing method is disclosed that utilizes a set of established user applications to access particular components of an operating system. A set of components of the operating system to be tested are established. Capabilities of a set of applications to access the components is established. The manner in which applications access the components is analyzed to establish classes. Furthermore, parameter sets are identified for each of the classes (e.g., functions). Test cases are created based upon combinations of parameter usages. Test calls are formulated by defining actual values to the parameter usages defined for the test cases.