Transitioning from federated avionics architectures to Integrated Modular Avionics

This paper identifies considerations for transitioning from a federated avionics architecture to an integrated modular avionics (IMA) architecture. Federated avionics architectures make use of distributed avionics functions that are packaged as self-contained units (LRUs and LRMs). IMA architectures employ a high-integrity, partitioned environment that hosts multiple avionics functions of different criticalities on a shared computing platform. This provides for weight and power savings since computing resources can be used more efficiently. This paper establishes the benefits of transitioning to IMA. To aid in the planning process, the paper also identifies factors to consider before transitioning to IMA. The approach to resource management (computing, communication, and I/O) is identified as the fundamental architectural difference between federated and IMA systems. The paper describes how this difference changes the development process and benefits the systems integrator. This paper also addresses misconceptions about the resource management mechanisms that can occur during a transition to IMA and concludes that resources are not inherently constrained by IMA architectures. Guidance is provided for transitioning to both "open" and "closed" IMA architectures. Open IMA architectures utilize open interface standards that are available in the public domain. Closed IMA architectures utilize proprietary interfaces that can be customized. The analysis of these avionics architectures is based upon the authors' experience in developing platform computing systems at GE Aviation. GE Aviation has developed open system IMA architectures for commercial aircraft (Boeing 787 Dreamliner), as well as military aircraft (Boeing C-130 combat aircraft, and Boeing KC-767 Tanker).