Requirements engineering for complex software intensive systems has become a major challenge in many software development projects. Especially the automotive industry experiences the increasing complexity of software in vehicles, during the last years. An actual premium vehicle, for instance embodies up to hundred electronic control units (ECU) with easily a few hundred features, each. (cf. ). Beneath the definition of abstract features, an electronic control unit is described by different goals, scenarios, requirements, and constraints. To create a manageable and traceable requirements specification for complex systems that enables the change and reuse of requirements, many companies claim assistance for a seamless specification of requirements. To satisfy this claim necessary requirements-artefacts have to be defined and abstraction levels have to be defined. Further the interrelations between different requirements-artefacts of one, and among different abstraction levels have to be analyzed and defined.