Software Engineering Institute

This paper examines issues relating to the impact of change in real-time control applications. In particular, Simplex-based systems are being considered, a technology that supports dependable upgrade of systems in a fault tolerant manner through the concept of analytic redundancy. Such systems provide flexibility to real-time systems for dynamic reconfiguration and dependable incremental and online upgrade. The paper focuses on offline analysis to determine inconsistencies in configurations and identify reconfiguration paths to recover to consistent configurations. The results are used by runtime configuration management to avoid such configurations. Identification of inconsistent configurations is improved through modeling of application semantics in the control domain and utilizing them in the analysis. The same analysis supports design time analysis of potential impact of changes.