eXpress’s Dynamic Models

Whether you call it conditional dependencies, multi-signal models or just plain dependency modeling, eXpress supports the model capture needed to handle dynamic systems. Under a NASA 2GRLV contract, the Dynamic Model capability was able to demonstrate both diagnostic statefulness through reconfiguration, as well as on-the-fly diagnostic creation in support of a dynamic IETM.

State Reconfiguration

• Dynamic States that influence Test Coverage, Functions and Failure Mode
• Support for Fault Detection Isolation and Remediation (FDIR)
• System Reconfiguration as part of normal changes during operation

Assessment of Dynamic Models

• Tests can be either intrusive or non-intrusive
• Construct and Assess Diagnostics for flight or ground maintenance
• Use the integrated FMECA capability with the Diagnostics to prove diagnostic coverage of safety critical failure modes

Dynamic Model Validation & Verification

• Ensure proper coverage in different modes of operation
• Verify that remediation actions exist for various FMECA-driven failures
• Use the entire model hierarchy to ensure that the true system impacts of lower level failures are understood and properly handled