Towards a continuous build-up process of a reusable requirements-based system model

The conceptual development process is the joint effort of designers and future operators to elicit and analyze requirements and to design a system which plausibly meets these requirements. A continuous build-up of a structured product model that explicitly interrelates system design and its metrics to requirements is desirable. However, requirements and system modeling are usually conducted separately using different tools. Moreover, the phases of the development process are often separated in time, personnel, and space. This practice leaves a considerable number of system design decisions untraceable. We address these problems by two propositions: (1) A use case which describes an iterative, concurrent, and continuous refinement process of the requirements and system model, and (2) a framework that allows the creation of an integrated system and requirements model and the gradual application of increasingly rigorous rules on the model. We demonstrate our approach by a simple conceptual aircraft design example and discuss whether our approach is scalable and promotes the reuse of model parts.