Skip to main content

​
Values

IDLabelSort OrderDescription
systemSystem0Top-level element representing the complete system under analysis (e.g., the vehicle or product). Anchors the decomposition hierarchy.
subsystemSubsystem1Major functional subdivision of the system (e.g., braking system, powertrain, infotainment network).
assemblyAssembly2Physical or logical grouping of components within a subsystem (e.g., sensor cluster, control unit housing).
subassemblySubassembly3Subdivision of an assembly (e.g., a PCB within a control unit, an individual hardware module).
componentComponent4Individual hardware or software component. Leaf node of the hierarchy. Directly associated with cybersecurity goals, damage scenarios, or threats.

​
Hierarchy Structure

System (Level 0)
  |-- Subsystem (Level 1)
       |-- Assembly (Level 2)
            |-- Subassembly (Level 3)
                 |-- Component (Level 4)
The five levels represent a containment hierarchy. Each level can contain elements of the next level down. Not all levels must be populated — simpler projects may skip intermediate levels (e.g., go directly from Subsystem to Component).

​
Field Binding

PropertyValue
Field IDelementType
Work Item TypesystemElement
Enum IDsystemElementType
Field TypeEnum (single-select)
The elementType field is defined as a custom field on the System Element work item type.

​
Hierarchy and Traceability

Components (leaf nodes) are the elements most commonly linked to:
  • Cybersecurity Goal work items — defining what security properties must be preserved
  • TARA Record work items — documenting threat scenarios against specific components
  • Threat Scenario work items — cataloging reusable threat patterns
The parent-child containment between hierarchy levels is implemented through link roles defined in the RTM Domain Model.

​
Lucene Queries

type:systemElement AND elementType:system
type:systemElement AND elementType:subsystem
type:systemElement AND elementType:assembly
type:systemElement AND elementType:subassembly
type:systemElement AND elementType:component
These queries enable filtering PowerSheet views or dashboard panels to display elements at a specific decomposition depth.

​
Usage in PowerSheet and Risksheet

Use CaseQuery Pattern
Show only leaf-level elementstype:systemElement AND elementType:component
Group analysis by decomposition depthRow grouping by elementType in PowerSheet
Filter TARA scope to a subsystemtype:systemElement AND elementType:subsystem
Collapsible hierarchy viewsPowerSheet expansion path following containment links between hierarchy levels

​
Configuration Notes

  • Sort order (0-4) reflects the hierarchy from top to bottom and controls display ordering in Polarion form dropdowns, column pickers, and Lucene result ordering.
  • The hierarchy is not strictly enforced by the enum alone. Whether a System must contain only Subsystems (and not Components directly) depends on link role cardinality rules defined in the RTM model YAML.
  • Solutions with deep hardware analysis may populate all five levels extensively. Software-centric projects may use only System, Subsystem, and Component.
  • The elementType field drives the system decomposition structure underpinning all TARA analysis. Consistent use of hierarchy levels across the project ensures meaningful coverage reporting and traceability chain analysis.