WF15: Conduct Critical Item Analysis

Pre-requisites

• SRA Module: The Safety and Risk Assessment module (SRA) enables access to Critical Item Analysis.
• FBD Model: Defined with function flows, failure diagrams and associated Criticality parameters.
• Assigned Criticality Data: Criticality data assigned across the model (see WF09).
• Criticality Profile: Default or custom criticality profile based on one of the existing criticality methods/types available in MADE.

Detailed Descriptions (numbered steps)

1. Access 'Critical Item Analysis' under 'Analyses' in the main menu bar.
2. Under Analysis Options, select 'End Effect' from the dialogue. The End Effect is an item that represents the highest level of the system affected by failure modes that will be considered for this analysis.
3. Select Propagation Type from the drop-down menu.
4. Select Appropriate Criticality Profile from the drop-down menu. This selection determines the Criticality Measure used to nominate Critical Items.
5. Enter the threshold value/category.
6. Select 'Calculate' to conduct the Critical Item Analysis.
7. Select 'Apply to Model' to flag listed results as Critical Items.
8. Flagged critical items can be viewed in the system model editor.

Outputs

• Critical Item List: 'Critical' items identified by the Critical Item Analysis may be exported as a .csv file.
• Top Critical Items: An exported PNG image of the graph showing the top critical items in the system.

Screenshot walkthrough (captions/labels extracted)

Step 1: Access Critical Item Analysis

• 'Analyses' menu: Fault Tree, Response Paths, Connection Matrix, Common Mode Analysis, Critical Item Analysis (highlighted), Criticality & Reliability Editor, Technical Budget Analysis, Failure Rate Prediction, Markov Analysis, RBD Analysis, Reliability Allocation Editor, Back-Fit RCM, Classic RCM, Maintenance Cost Estimates.
• "Critical Item Analysis" tab: "Analysis Options" (End Effect "Vehicle System", Propagation Type "FCM", Criticality Profile "PHMT RPN Criticality"); "Criticality Thresholding" note "Select a Criticality Profile above to threshold by and then select Calculate to continue," with empty table and pencil/edit icon, "Calculate" button. Right panel "Top Critical Items" ("No critical items to graph") and "Critical Items" table (columns Item, Criticality/Risk, Severity, Parent, Item..., Rep..., Occ..., Diff..., Co...) with buttons Apply to Model, Clear Critical Items.

Step 2: Select End Effect

• Analysis Options panel with End Effect field highlighted ("Vehicle System"). "Select an End Effect" dialog: "Select the End Effect to be used for analysis." Tree: [VS1] Vehicle System (selected) > Coupling, Driveline, Power Generation, Vehicle. Buttons OK, Cancel.

Step 3: Select Propagation Type

• Analysis Options panel with Propagation Type dropdown expanded showing FCM (highlighted) and Bond.

Step 4: Select Criticality Profile

• Criticality Profile dropdown expanded listing: PHMT Fuzzy Criticality (Type "Fuzzy Criticality"), PHMT Risk Assessment Criteria (FAA) (highlighted, Type "ARP 4761 (Rev A)"), PHMT Risk Assessment Method (RAC) (Type "MIL-STD-882E"), PHMT ISO26262 Criticality (Type "ISO26262"), PHMT RPN Criticality (Type "Risk Priority Number (RPN)"), PHMT 1629A Criticality (Type "MIL-STD-1629A") — each owned by "PHM Technology Pty. Ltd."

Step 5: Define Criticality Threshold

• "Criticality Thresholding" table with a "Risk" column header and pencil/edit icon; "Calculate" button. "Critical Item Filters - ARP 4761 (Rev A)" dialog: "Set one or many Criticality Filters to be applied to the current profile." Fields: Risk checkbox "Threshold:" dropdown (options Low, Medium, High — High selected); Severity checkbox "Threshold:" dropdown (unchecked/empty). Buttons OK, Cancel.

Step 6: Calculate Criticality Item Analysis

• Second "Critical Item Filters - ARP 4761 (Rev A)" dialog showing Risk Threshold = Low (checked), Severity Threshold unchecked. "Criticality Thresholding" table populated with column "Risk" = "Low"; "Calculate" button highlighted.

Step 7: Assign Results as 'Critical Item'

• "Critical Item Analysis" fully populated: Analysis Options (End Effect "Vehicle System", Propagation Type "FCM", Criticality Profile "PHMT Risk Assessment Criteria (FAA)"), Criticality Thresholding (Risk = Low). "Top Critical Items" bar chart: x-axis "Risk - ARP4761 Threshold: Risk" categories Low/Medium/High, y-axis Count 0-20; Medium bar ≈19 (orange), High bar ≈5 (dark red), Low bar 0.
• "Critical Items" table (highlighted): buttons Apply to Model, Clear Critical Items. Columns: Item, ARP4761 Risk, Severity, Parent, Item No., Replaceable, Occurrence/Proba... Rows: Control Unit (High, Catastrophic, Power Generation, Probable); Coupling 1 (High, Catastrophic, Diesel Engine, Probable); Engine (High, Catastrophic, Diesel Engine, Probable); Inlet (High, Catastrophic, Fuel Tank, Probable); Lining (High, Catastrophic, Fuel Tank, Probable); Coupling, Differential, Driveline, Driveshaft, Governor, Half Shaft Front/Rear, Injector Pump, Lift Pump, Planetary Gearbox Front (all Medium, Catastrophic, various parents, "Extremely Improbable").

Step 8: Critical Item Analysis Conducted

• Project Explorer tree: Vehicle System [4/29] > Coupling, Driveline [11/11], Power Generation [3/14] > Control Unit, Diesel Engine [8/8], Fuel Tank [3/3] > Pairs [2] (Inlet_Lining, Lining_Outlet), Inlet, Lining, Outlet; Vehicle.
• "Vehicle System" canvas (Mission Profile: New Group; End Effect Item: Vehicle System) showing Power Generation (flagged with red warning icon) → Coupling → Driveline → Vehicle, feeding IN/OUT.
• "Power Generation" canvas: Fuel Tank → Diesel Engine (flagged red warning), Control Unit (flagged red warning) → Diesel Engine, feeding IN/OUT.
• "Fuel Tank" canvas: Inlet (flagged red warning) → Lining (flagged red warning) → Outlet, feeding IN/OUT.

Related workflows

• WF09 – Perform Criticality Editing (criticality data assignment prerequisite)