WF68: Link FHA Functions to System Model

Pre-Requisites

• A. Functional Hazard Assessment: Functional Model with all the failure condition(s) and multiple failure event(s) defined (see WF36, WF37, and WF61).
• B. System Model: Logical model containing model items.

Detailed Steps

1. Select the system and open the 'Functional Diagram' found in the 'Modeling' tab of the menu bar, or via the right-click context menu opened on the system in the Project Explorer.
2. Navigate to the Functional Diagram canvas, right-click and select 'Link to System Model' from the context menu.
3. In the Functional Model Linking window, select Function(s) from the 'Functional Model' section that will be linked to the system model. All the single failure conditions present within the function are selected by default. A Function without a single failure condition is disabled for selection.
4. In the Functional Model Linking window, select model item(s) from the 'System Model' section.
5. Click the 'Create Link' icon to establish the linkage between the selected function(s) and model item(s). The logical function and failure diagram editors open for the selected model item(s), confirming the linkage.
6. Decision — All Functions linked? If no, select Functional Diagram editor to continue linking functions with system model (return to Step 2). If yes, Functions linked to System Model.

Screen-by-screen detail (from embedded screenshots)

• Step 1: Open Functional Diagram — Project Explorer, right-click system > select "Functional Diagram" (alongside New, New Diagnostic Analysis, System Model, Failure Diagram, Bond Graph, Functions, Requirements, Mission Profiles, Diagnostic Analyses, Maintenance Actions). Opens Functional Diagram canvas showing top-level functions (e.g. "Control Vehicle", "Provide Thrust") with sub-elements (e.g. "Crew Alerting", "Air/Ground Determinations" under "E3 - Support Systems"). Below, a "Functions List" table (Function/Failure Condition, Level, Mission Sections, Initial Severity Class, Revised Severity Class, Comments).
• Step 2: Open Functional Model Linking Editor — Right-click a function block (e.g. "Provide Thrust") on the canvas > context menu includes New, Import, Functional Diagram, Failure Conditions, Domain Editor, Cut/Copy/Paste, Delete, Zoom In/Out, and "Link to System Model...". Opens the "Functional Model Linking" dialog: "Link Functions from the Functional Model to Components or Functions in the System Model." Left pane "Functional Model" tree (e.g. Control Vehicle > Control Vehicle Direction, Decelerate Vehicle; Provide Thrust > Convert Fuel to Mechanical Motion, Distribute Mechanical Motion). Right pane "System Model" tree (e.g. Control Unit > Process, Diesel Engine > Convert, Air Filter > Refine, Coupling 1 > Couple, Engine > Convert, Governor > Control, Injector Pump > Regulate, Lift Pump > Increase) with a "Linked Function" column.
• Step 3: Select Function(s) — Select a function in the Functional Model tree, e.g. "Convert Fuel to Mechanical Motion" (only functions containing one or more Failure Conditions can be linked).
• Step 4: Select Model Item(s) — Select a corresponding item in the System Model tree, e.g. the "Convert" function under "Engine".
• Step 5: Click 'Create Link' icon — Click the link/chain icon between the two panes. The "Linked Function" column populates for the selected System Model item (e.g. "2.1 - Convert Fuel to Mechanical Motion"). Click Finish.
• Step 6: Select Functional Diagram Editor — Back in the Functional Diagram editor, the Functions List now shows nested Failure Modes for linked functions (e.g. under "2 - Provide Thrust" > "2.1 - Convert Fuel to Mechanical Motion" > "Failure Modes" > "1 - Inability to Convert Fuel to Mechanical Motion", and "2.2 - Distribute Mechanical Motion"), confirming the link was established.