GSN Assurance Models

SEAM supports the Goal Structuring Notations (GSN) standard to build assurance case models. SEAM uses hierarchical models, as well as cross-referencing to manage complexity in GSN models. Additionally, SEAM allows linking assurance cases to system models to provide context to the assurance case argument.

System Models

SEAM supports a subset of block diagram models in the SysML modeling standard. These include functional (hierarchical requirement) models and architecture design with block diagram models.

Fault Models

SEAM extends the internal block diagram models to allow specification of discrete fault propagation to capture the faults and their anomalous effects within a block (subsystem) and their propagation across the system through subsystem interfaces.

Integrated Models

SEAMS allows context specification through cross-referencing of modeling entities across the models. Functional models are cross-referenced in the system fault propagation models to capture the impact (function loss or degradation) of and response (mitigation function) to failure effects. Sub-system models that implement specific functions are cross-referenced in functional models. Subsystem and functional models are cross-referenced in the GSN assurance case models to provide context to the argument.

NASA R&M Hierarchy

NASA's Reliability and Maintainability Standard serves as a template to build radiation hardness assurance cases for using COTS systems in space missions. SEAMs provides template models of the R&M hierarchy to kick-start the assurance case development.


A set of examples is available including:


    Collaborate with your colleagues by simultaneously working on the same project. SEAM uses the WebGME modeling framework that works just like Google Docs; it updates and shows all changes to each user concurrently. And you never lose work because the models are stored in a database in the cloud.


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