WF07: Generate Response Paths

Pre-requisites

• FBD Model: for the responses to propagate throughout, generating the response paths.
• Failure Diagrams: provides detail on physical failures in the generated response paths.
• Criticality Factors: provides criticality details in the generated response paths.
• Bond Modeling: only model items defined with bond types and without errors, may generate bond response paths.

Detailed Descriptions (numbered steps)

1. Select a model item / level of indenture and access 'Response Paths' under 'Analyses' in the main menu bar or via the right-click context menu.
2. Response paths will be generated in FCM or Bond, depending on which modeling method used.
3. Select 'FCM' to generate response paths with FCM.
4. Select 'Bond' to generate response paths with Bond.
5. There is the option to reduce the number of response paths displayed, to only show root causes.
6. Select the icon with the tool-tip 'Root Causes Only'.
7. There is the option to increase the number of response paths displayed, to also show nominal paths.
8. Select the icon with the tool-tip 'Show Nominal Paths'.
9. Select the Criticality Method to be displayed in the Response Paths viewer, from the drop-down menu.
10. Review response paths to ensure all have been identified and are accurate. Make any necessary changes to the model to achieve this.
11. Response paths have been generated.

Fields referenced in the diagram

• Select Criticality Type options: RPN, Fuzzy Criticality, FAI

Decision points

• Generate with FCM? — Yes → Generate with FCM; No → Generate with Bond.
• View Root Causes Only? — Yes → Show Root Causes Only; No → continue.
• Show Nominal Paths? — Yes → Show Nominal Paths; No → continue.

Outputs

• Response Path Data Table: may be exported as a .csv file.

Screenshot walkthrough (captions/labels extracted)

Step 1: Access Response Paths

• 'Analyses' menu: Fault Tree, Response Paths > (FCM, Bond), Connection Matrix, Common Mode Analysis, Critical Item Analysis, Criticality & Reliability Editor, Diagnostic Analyses, Failure Rate Prediction, Markov Analysis, RBD Analysis, Reliability Allocation Editor, Back-Fit RCM, Classic RCM, Maintenance Cost Estimates.
• Right-click context menu on "Driveline" (Vehicle System canvas): System Model, Failure Diagram, Bond Graph, Functions, Maintenance Actions, Cut/Copy/Paste, Delete, Zoom In/Out, End Effect Item, Fault Tree, Response Paths > (FCM, Bond) — highlighted, Propagate All..., Override Failure Diagram, Failure Injection, Response Simulation, Save to Library, Advanced Properties.
• Project Explorer tree shown expanded: Vehicle System [4/29] > Driveline [11/11] > Differential, Driveshaft, Half Shaft Front, Half Shaft Rear, Planetary Gearb[ox Front/Rear], Transmission, Wheel Front, Wheel Rear, Wheel Resistanc[e Front/Rear] > Power Generation [...] > Control Unit, Diesel Engine [8/8], Fuel Tank [3/3].

Step 3: Generate with FCM

• "Response Paths - FCM" table with columns Cause, Local Effect, Next Higher Level, End Effect. Tree grouped by Vehicle System (416 rows), Coupling (4), Driveline (68), sub-grouped by Differential (4), Driveshaft (4), Half Shaft Front (2), Half Shaft Rear (2). Example rows: "Branch Mechanical - rotational Angular velocity High (Driveline)" → Local Effect "Convert Mechanical - rotational Angular velocity High (Vehicle System)" → chained to End Effect "Convert Mechanical - rotational...". Rows include causes like "Connect Mechanical - rotational Angular velocity Low (Vehicle)", "Couple Mechanical - rotational Torque Low (Coupling)", "Distribute/Divide/Rotate/Store/Support/Transmit Mechanical..." variants per component.

Step 4: Generate with Bond

• "Response Paths - Bond" table, same column layout, grouped by Vehicle System (640), Power Generation (638), Control Unit (96), Diesel Engine (270), further grouped by Air Filter (32), Coupling 1 (16), Engine (52), Governor (24), Injector Pump (28), Lift Pump (28), Primary Fuel Filter (32), Secondary Fuel Filter (32). Example rows: "Control Mechanical - linear Linear velocity Low (Governor)" → Local Effect "Convert Mechanical - rotational Torque Low (Power Generation)" (some rows show "N/A" for Next Higher Level); "Couple Mechanical - rotational Angular velocity High (Cou[pling])" → "Convert Mechanical - rotational Torque High (Diesel Engine)".

Step 6: Show Root Causes Only

• "Response Paths - FCM" table filtered ("Root causes only" tooltip shown), reduced to 308 rows under Vehicle System, grouped by Coupling (4), Driveline (44) > Differential (4), Drivehaft (4), Half Shaft Front (2), Half Shaft Rear (2), Planetary Gearbox Front (2), Planetary Gearbox Rear (2), Transmission (4), Wheel Front (6), Wheel Rear (6, partially visible). Example rows: "High mechanical load (Coupling)" → "Couple Mechanical - rotational Torque Low (Coupling)"; "Divide Mechanical - rotational Angular... (Diff[erential])" → "Branch Mechanical - rotational Angular velocity...".

Step 6: Show Nominal Paths

• "Response Paths - FCM" table with "Show Nominal Paths" tooltip shown, expanded to 416 rows under Vehicle System, including additional causes without red warning icons (nominal, non-failure paths) such as "Branch Mechanical - rotational Angular vel[ocity]...", "Connect Mechanical - rotational Angular v[elocity]...", "Convert Mechanical - rotational Torque Lo[w]...", "Couple Mechanical - rotational Torque Low...", plus Coupling (4) and Driveline (68) sub-groups.

Step 9: Select Criticality Type

• Dropdown menu (funnel icon) listing criticality methods: RPN, Fuzzy Criticality, FAI, HRI, ARP, MIL-STD-882E, ISO 26262.
• "Response Paths - FCM" table showing criticality columns: Cause, Local Effect, Next Higher Level, End Effect, S (Severity), FEP, FMR, FR, Op. Time, Crit. #, S. Class., with example values (S=10.0, FEP=1.0, FMR=0.5 or 0.25, FR=1.0 or 5.133333333339013, Op. Time=91.0, Crit.#=4.55E-5 or 1.1678E-4, S. Class.="Category I - Catastrophic", and a rightmost column with values like "Unacceptable").

Step 11: Response Paths Generated

• Final "Response Paths - FCM" table with columns Cause, Local Effect, End Effect, Occurrence, Severity, Detectability, FAI, Apparent Occurrence, HRI Risk. Example rows for Vehicle System (416): "Branch Mechanical - rotational Angular velocity High (Driveline)" with Occurrence 1.0, Severity 10.0, Detectability 10.0, FAI 2.238E-04 ("Infrequent B"), Apparent Occurrence "Very Low (1.3)", HRI Risk "Medium"; other rows show higher-risk entries such as "Connect/Convert/Couple Mechanical..." with Apparent Occurrence "Moderate (6)" / "High (7.5)" / "High (6.8)" and HRI Risk "Extreme". Grouped sections for Coupling (4) and Driveline (68) with sub-items Differential (4), Driveshaft (4), Half Shaft Front (2), Planetary Gearbox Front (2).

Related workflows

• Uses Failure Diagrams (WF06) and Criticality profiles/editing (WF09) as inputs.