Fcsr task: application of SAE ARP-4754A to the development of complex and safety-critical systems 1.0 introduction/background: this effort supports NASA's aviation safety programs system-wide safety…

Fcsr task: application of SAE ARP-4754A to the development of complex and safety-critical systems 1.0 introduction/background: this effort supports NASA's aviation safety programs system-wide safety assurance technologies (ssat) project which is conducting research directed at improving the safety of current and future aircraft operating in the national airspace system. Under ssat there is a technical challenge that targets the assurance of flight critical systems (afcs) a technical challenge that addresses, among other things, the sound assurance of safety-critical distributed systems properties and the complex interactions between systems and subsystems. There is an ongoing trend in the aviation industry of increasing adoption of ever more sophisticated computer-based technology to realize aircraft systems performing a wide variety of functions with different safety criticality levels. State-of-the-art aircraft avionics are network-centric systems of systems that are highly complex, software-intensive, and functionally integrated. The use of legacy components and multiple vendors to supply different functions that must share resources on a common distributed platform adds further complexity to these systems. The intricate patterns of interaction resulting from large-scale functional integration and distributed processing can expose a system to many non-intuitive failure mechanisms with a potential for severe safety-relevant effects. The level of rigor in the development process is determined by considerations of complexity and safety criticality. The predictability and robustness of the integrated system in the face of uncertainty in interactions and health status of components is of major importance in the certifiability of the system. The SAE international (formerly the society of automotive engineers [SAE]) aerospace recommended practice 4754, revision a (ARP-4754A) describes a recommended process-based development assurance framework for systems that implement and support aircraft-level functions. The purpose of ARP-4754A is to provide guidance for the generation of evidence to substantiate with adequate confidence (i.e., assurance level) that errors in requirements, design, and implementation of the system have been identified and corrected and that the system satisfies the applicable certification regulations. ARP-4754A states what objectives need to be accomplished based on system development assurance level (DAL) assignments, but IT does not provide a justification for the guidance and its application requires significant engineering judgment. 2.0 scope & objective(s): 2.1 the scope of this task is for a study on the application of ARP-4754A to the development of modern computer-based (i.e., digital electronics, software and network-based) aircraft systems. This study is to offer insight and have pedagogical value relative to the guidelines in ARP-4754A and provide an assessment of the current state-of-the-practice within industry and regulatory bodies relative to development assurance for complex and safety-critical computer-based aircraft systems. 2.2 the objectives of this task order are: perform between one and four case studies on the application of ARP-4754A to the development and assurance of computer-based aircraft systems with architecture-level complexity representative of state-of-the-art technology, generate guidelines on the application of ARP-4754A to the development and assurance of computer-based aircraft systems, and identify issues of concern in the current guidance, policy, and practice (i.e., processes, methods, tools or techniques) of development and assurance for computer-based aircraft systems. 3.0 description of the work/tasks to be performed: the contractor shall perform the following tasks: 3.1 case studies on the application of ARP-4754A the contractor shall perform between one and four