Experiences gained from modeling and solving large mapping problems during system design

The rising complexity of embedded control systems and their increasing application to automate safety-critical or mission-critical tasks present a challenge for established development methodologies and tools. Are they able to handle the growing system complexity without compromising either system efficiency or its correctness? This challenge is addressed by the "correctness by construction" engineering principle. It aims to formalize error-prone and cumbersome engineering tasks to ensure correctness as well as efficiency despite high levels of complexity. A major obstacle in applying this principle in practice lies in the necessary formalization of "constructive tasks" for which human engineers with creative minds are still predominantly responsible. The authors applied this principle to "mapping problems", which occur during the design of several real-world embedded control systems. The tool suite ASSIST was developed to automate the "mapping process" and demonstrate the feasibility of this approach. It takes textual specifications of a mapping problem and its constraints as input from the systems engineer and uses Constraint Programming to synthesize valid and optimized solutions. In this contribution, the experiences gained from modeling and solving large-scale mapping problems as part of the design of embedded control systems are described in detail.