|SafeAir will contribute to the overall goal of facilitating aircraft subsystem and component development in order to foster the competitiveness of the European avionics industry. Its focus is on substantially improving the electronic system development process, leading to a 35-40% reduction in development cost for airborne software systems. This will give European Avionics Industry process leadership in systems- and software development. Beyond this, the exploitation potential addresses a wide range of European industries with similar challenges.
SafeAir will develop a model-based methodology for designing dependable embedded systems. The approach will be based on the integration of mature, well-accepted notations and tools integrated in a usable development environment. The result will ensure a high degree of dependability of avionics systems in spite of ever increasing complexity. Salient novel features are rigorous verification of critical properties, automated, certified code generation and automatic validation of the code with respect to the design.
SafeAir aims at the development of an Avionics Systems Development Environment (ASDE), encompassing technologies, methods and tools that meet the high dependability needs in the area of embedded control systems. Challenges in designing and developing such systems for avionics and other industrial application of similar complexity span the whole development cycle. Requirements need to be described unambiguously and correctly, the design, code and implementation must be checked for correctness and reliability with respect to the requirements. At the same time, the development effort must be kept low to meet the tight time to market. SafeAir's goal is to substantially improve the electronic and embedded systems development process, allowing to maintain the high level of dependability of aircraft systems in the face of an exponential growth in functionality and complexity. The proposed improvements aim at a dramatic reduction in development effort for airborne software systems and its consequent reduction in development cycle time.
European avionics industry typically uses variations of the V-process model to structure the development process of airborne software which will be defined as the reference model. This model is compliant with the DO-178B recommendations in commitment with certification authorities worldwide: FAA and JAA. The figure below indicates, how SafeAir proposes to gradually improve a V to a Y-based process, in order to significantly reduce the design time. The slope of curves is selected to qualitatively indicate the time consumed in particular design steps.
SafeAir supports an incremental, two-stage road for process improvements, each leading to successive reductions in development costs and design time, while maintaining, or increasing, system reliability. The key concepts for these improvements are a model based design process, automatic code generation and formal verification. An Aircraft System Development Environment (ASDE) implementing these concepts will be developed and evaluated in the project. This integrated environment will be built on the verification and validation technologies developed in the SACRES Esprit project and expand them to a mature tool set, responsive to user needs. SafeAir will secure that proposed enhancements in the design methodology will be acceptable for the DO178B and ARP4754 certification authorities.
To ensure both the technical development and the user take-up, the project combines technology providers and vendors with skilled teams from user companies. The applications cover the entire development from system and subsystem specification to software implementation in the aeronautics sector.
The major result of SafeAir will be a validated ASDE for system and software development. This environment will support system specification and software specification, on the basis of formal, readable notations both at the analysis and design phase, and integrate de-facto standard modelling tools for avionics applications.
ASDE will significantly raise the degree of early error detection and reduce the validation effort at integration time through formal verification techniques for the verification of critical properties. It will provide a seamless integration from system-level modelling tools to an automatic code generation tool in compliance with the DO-178B standard for critical airborne embedded systems. Automatic generation of distributed code will be supported.
The method includes an innovative approach for automatically proving consistency of source and generated code supporting the complete translation chain down to the binary level, thereby eliminating potential coding errors and allowing a dramatic reduction of unit testing. This approach constitutes a major technological breakthrough providing valuable certification evidence for the users. As a result of introducing and assessing ASDE within aerospace engineering processes and as the basis for technology dissemination, a comprehensive assessment report as well as an assimilation and training package will be provided.