Functional Failure Analysis (FFA)
After you have determined which pieces of equipment will be analyzed with RCM techniques, the next step is to perform a functional failure analysis on the equipment. You do this in a manner similar to creating a Failure Modes and Effects Analysis (FMEA).
Tip: This section provides basic instructions for this portion of the analysis. The FMEA Analysis section of this documentation provides more detailed information about the features available in the Analysis panel, including alternative data entry options and a list of the properties that can be defined for each record type.
- Select an item in the system hierarchy and choose Analyses > FMEA > Add FMEA. The FMEA analysis tab will open in the Analysis panel. In addition, the FMEA icon (F) will appear in the FMEA column in the system hierarchy, if the column is displayed.
When working in the Analysis panel, you have a choice of several ways to enter and edit the information. To use one of these views, click its tab at the bottom of the Analysis panel.
- The Hierarchy view displays the analysis records defined in your analysis (e.g., functions, actions, etc.) at a glance in a hierarchical tree structure. For more information about using this view, refer to FMEA Hierarchy View.
- The Worksheet view displays the functional failure analysis in a tabular format. The worksheet presents a column for each data field that has been enabled in the interface style for the project. For more information about using this view, refer to FMEA Worksheet View.
- The Alpha/Beta Ratios worksheet allows you to calculate the likelihood of each effect occurring, assuming a known overall failure rate for the item. For more information, refer to Alpha/Beta Ratios Worksheet.
- The Filtered view displays only records of a specific type (e.g., functions, tasks, etc.). Choose the record type that you want to view from the drop-down list at the upper right corner of the Analysis panel. For more information about using this view, refer to FMEA Filtered View.
- Describe the functions the equipment is intended to perform.
To add a function to the analysis, choose FMEA > FMEA Records > Functions and then provide information about what functions the equipment is intended to perform (e.g., for an airplane fire extinguishing system, a function might be "Store extinguishing agent under pressure").
- Describe the potential functional failures.
To add a functional failure to the analysis, choose FMEA > FMEA Records > Failures and then provide information about the ways that the equipment might fail to perform its intended functions (e.g., for an airplane fire extinguishing system, a functional failure might be "Fails to maintain full quantity of agent at correct pressure").
- Describe the effects of each functional failure.
To add an effect to the analysis, choose FMEA > FMEA Records > Effects and provide information about the potential consequences if a failure occurs (e.g., for an airplane fire extinguishing system, an effect might be "Insufficient agent available in the Fire Extinguisher bottle for effective discharge").
- Describe the potential failure modes.
To add a failure mode to the analysis, choose FMEA > FMEA Records > Causes and provide information about the specific reason for the functional failure at the actionable level (e.g., for an airplane fire extinguishing system, a failure mode might be "Leakage from Fire Extinguisher bottle assembly").
The following sections describe how to apply an RCM logic diagram and/or cost-based comparisons in order to determine the appropriate maintenance strategy to address the issues that have been identified in the functional failure analysis.