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Reliability Improvement and Validation Framework

Special Report
This report discusses the reliability validation and improvement framework developed by the SEI. The purpose of this framework is to provide a foundation for addressing the challenges of qualifying increasingly software-reliant, safety-critical systems.

Software Engineering Institute

CMU/SEI Report Number
DOI (Digital Object Identifier)


Software-reliant systems such as rotorcraft and other aircraft have experienced exponential growth in software size and complexity. The current software engineering practice of "build then test" has made them unaffordable to build and qualify. This report discusses the challenges of qualifying such systems, presenting the findings of several government and industry studies. It identifies several root cause areas and proposes a framework for reliability validation and improvement that integrates several recommended technology solutions: validation of formalized requirements; an architecture-centric, model-based engineering approach that uncovers system-level problems early through analysis; use of static analysis for validating system behavior and other system properties; and managed confidence in qualification through system assurance. This framework also provides the basis for a set of metrics for cost-effective reliability improvement that overcome the challenges of existing software complexity, reliability, and cost metrics.