X-by-Construction EU Research Project XANDAR Successfully Finished

The development of embedded electronic systems for self-driving cars, autonomous air taxis and similar safety-critical applications is subject to several constraints. In the XANDAR project, Vector has joined forces with seven European partners to explore new approaches to this complex challenge. After three years, the consortium presents an automated toolchain, tailored to the context of novel mobility solutions, that helps developers meet essential safety, security, and real-time requirements. An integral part of this XbC toolchain are Vector's PREEvision and TA Tool Suite products.?

The functional and non-functional requirements that software must meet in embedded electronic systems are becoming increasingly complex. To date, many of the steps involved in the development process depend on manual activities by the developer, which can make the process very time-consuming, expensive, and potentially error-prone.?

Model-Based Transformation and System Integration: From Specification to Realization?

In the recently completed XANDAR project, a balanced European consortium of industry and academia explored and developed concepts for end-to-end automation of these steps. To achieve this, the partners used a novel approach: X-by-Construction (XbC).

In this paradigm, desired system properties are formally captured and refined through a stepwise transformation process into a correct, executable realization of the software system. In general, this approach can be applied to a variety of non-functional requirements. In the consortium, the newly developed concepts have been applied in particular to meet application-specific safety, security, and real-time requirements.

The resulting approaches, developed by the consortium between January 2021 and December 2023, were integrated into a prototypical toolchain. As part of this integration process, the XANDAR partners developed a dedicated software layer running on modern multicore platforms to provide the toolchain with important runtime mechanisms. Vector's expertise as an embedded software specialist and its high-performance development environments PREEvision and TA Tool Suite contributed to the achievement of the project's ambitious goals.??

PREEvision, Vector's model-based E/E engineering tool, was used for the platform architecture description. In addition, the XANDAR development process revealed the need for behavior specifications based on SysML. The resulting customizing in PREEvision improves the overall workflow, traceability, and quality of work products.

Another improvement were the continuous specification, verification, and validation of timing properties. The use of timing specifications at multiple levels of abstraction throughout the development improves understanding and aims to better support the process. Prototype extensions for the timing specification were realized in PREEvision and TA Tool Suite. For more details, see this article:

Additionally, the consortium identified specific tool scenarios where the degree of automation within the toolchain could be significantly increased.?

Successful Application of the Toolchain in the Automotive and Aerospace Context?

The concepts and prototypes were evaluated in two use cases. In the course of the project, the German Aerospace Center (DLR) and the BMW Group (BMW) applied the developed approaches to system designs in their respective domains. For example, the novel XbC toolchain was applied to a pilot assistance system for urban air mobility and a sensor fusion system for autonomous road vehicles.?

The partners see the achieved results as a promising approach to reducing risks and costs in the area of modern parallel software systems. At the same time, they point out the complexity and emphasize that the toolchain developed in the project represents a first step on the way to an automated, model-based XbC solution.