FTA Risksheet documents support the systematic decomposition of failure conditions and hazards into their contributing causes. The FTA configuration integrates with ARP 4761 safety assessment workflows, allowing engineers to:
Link failure conditions from the Functional Hazard Assessment (FHA) to contributing fault events
Trace failures through intermediate events to primary (root cause) events
Document mitigation strategies and risk controls addressing identified root causes
Track verification status and alignment with safety requirements
FTA Risksheet configuration details in the Aerospace Safety Solution are available in the live Polarion instance. Complete configuration validation is recommended in your project environment.
The FTA template is registered in the project configuration and can be used to create new FTA analysis documents. Unlike component-level DFMEA documents, FTA documents are system-scoped and analyze failure conditions at the system level.
While FTA events are stored as individual work items in the risksheet, the logical relationships between intermediate and primary events can be documented through:
Gate Type
Representation
Description
AND Gate
Multiple causes links from single intermediate event
All contributing causes must occur for the event
OR Gate
Single intermediate event with one causes link from multiple primaries
Any single cause can result in the intermediate event
Combined
Mixed links
Complex fault paths with both AND and OR logic
Documentation of gate type is recorded in the contributingFactors or rootCause field for reference during analysis.
The work-item-based FTA representation does not enforce strict Boolean logic validation. Engineers should document gate logic clearly in event descriptions and verify complex fault paths outside the risksheet as needed.
FHA Failure Condition
↓ [analyzedBy]
FTA Top Event
↓ [causes / AND-OR logic]
Root Causes (Primary Fault Events)The FTA top event is always linked to a specific failureCondition from the FHA using the analyzedBy role.
FTA Fault Event
↓ [mitigatedBy]
Risk Control (design/operational)
↓ [verifiedBy]
Verification Activity (test, analysis, inspection)Each primary fault event should have one or more risk controls assigned, and each control’s verification method and status should be tracked.
Fault events at all levels can link to safety requirements that were derived from the fault tree analysis:Fault Event (any level)
↓ [addresses / allocatesTo]
Safety Requirement
↓ [decomposesInto]
Design Requirement or Test Case
PDF Report — Fault tree diagram (manual), event listing, control mapping, verification summary
Excel/CSV — Work item data for further analysis or external tool import
DOORS Next / ALM Integrations — Cross-tool traceability and compliance reporting
Export and report generation capabilities depend on your Aerospace Safety Solution configuration and Polarion plugins. Consult your system administrator or documentation for available export formats.
