Processes for developing safety-critical systems impose special demands for ensuring requirements traceability. Achieving valuable traceability information, however, is especially difficult concerning the transition from requirements to design. Bernhard Turban analyzes systems and software engineering theories the problem is cross-cutting in (embedded systems development, systems engineering, software engineering, requirements engineering and management, design theory and processes for safety-critical systems). As a solution, the author proposes a new tool approach supporting designers in their thinking in order to achieve traceability as a by-product to normal design activities and extending traceability information with information about desgin decision rationale.