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Prerequisites

  • A project created from the Medical Device Safety Solution template
  • Understanding of your device’s physical and functional architecture

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Understanding the System Element Hierarchy

The solution supports a five-level product decomposition: diagram Each level is classified using the elementType field, which references the systemElementType enumeration:
Element TypeSort OrderDescription
system1Top-level product (e.g., “Smart Infusion Pump”)
subsystem2Major functional grouping (e.g., “Fluid Delivery System”)
assembly3Integrated unit (e.g., “Pump Mechanism Assembly”)
subassembly4Sub-unit within an assembly
component5Individual part (e.g., “Pressure Sensor”)

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Step 1: Open the System Element Tree Document

  1. Navigate to the Requirements space in Polarion
  2. Open the System Element Tree document
  3. The document uses the parent link role for hierarchical nesting
The document is named “System Element Tree” (not “System Elements”) to emphasize the hierarchical tree structure. It uses structureLinkRole: parent for nesting.

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Step 2: Create the Top-Level System Element

  1. Click Add Work Item in the document
  2. Set the work item type to systemElement
  3. Enter the device name as the title (e.g., “Smart Infusion Pump”)
  4. Set elementType to system

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Step 3: Add Subsystems

For each major functional area of your device:
  1. Add a new systemElement work item as a child of the system element
  2. Set elementType to subsystem
  3. Name it descriptively (e.g., “Fluid Delivery Subsystem”, “User Interface Subsystem”)
Subsystem names become scoping identifiers for DFMEA documents. The DFMEA risksheet uses a queryFactory that filters functions by the subsystem they belong to.

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Step 4: Decompose Further (Assembly, Subassembly, Component)

Continue decomposing each subsystem into assemblies, subassemblies, and components as needed. Use the parent link to nest items within the document structure. The hierarchy depth should match your device’s actual architecture:
  • Simple devices: System > Subsystem > Component (3 levels)
  • Complex devices: All 5 levels for full IEC 60601-based decomposition

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Step 5: Verify the Hierarchy

After creating all system elements:
  1. Review the document outline to confirm the hierarchy is correct
  2. Verify each element has the correct elementType classification
  3. Check that subsystem elements are properly nested under the system element
The solution references the hierarchy in several places:
ConsumerHow It Uses System Elements
DFMEA risksheetFunctions are allocated to system elements via allocatedTo link role
DFMEA top panelResolves subsystem from parent system element for document scoping
PFMEA risksheetProcess steps associate with system elements via associates link role
DFMEA Summary ReportQueries subsystem elements to label each DFMEA module
Process Steps sheetPowerSheet displays linked system elements per process step
After creating the system element hierarchy, create function work items and link them to system elements:
  1. Create a Functions document for each subsystem
  2. Add function work items describing what each component does
  3. Link each function to its system element using the allocatedTo link role
  4. These functions become the Level 1 grouping in DFMEA risksheets

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Next Steps

Configuration: .polarion/tracker/fields/systemElement-custom-fields.xml | Enumeration: systemElementType-enum.xml | Document: modules/Requirements/SYSTEM-ELEMENTS/module.xml