*
Concepts
*
Tasks
*
Settings

Creating SIF Failure Modes

A failure mode is a single event that causes a functional failure. For example, if a fill level sensor fails, a tank can overflow, causing a safety hazard. The safety analysis team studies assets to determine loss of containment scenarios, identify risk levels, decide whether a safety instrumented system is required, and define the provisions that protect against, or mitigate, loss of containment.
Each failure mode is associated with a HAZOP checklist item, such as “high pressure,” “slow reaction”, or “low level”. Checklist items are automatically included when the failure mode is created so that you can select the relevant one. You can also exclude checklist items and browse for additional ones.
Tip: You can view the HAZOP checklist items assigned to failure modes in a SIF analysis. In the Strategy Development Analysis window, select the Implementation view and the HAZOP Audit tab. Use the options in the Configuration list to view failure modes arranged by checklist item or checklist items that are not included on failure modes.
This section explains how to create an individual failure mode using the Maintenance Action Plan window.

To Create a Failure Mode

1.
Open the analysis, select the Facilitation view, and then the Info Worksheet tab.
2.
Make sure that editing is enabled.
3.
Select the HAZOP checklist item appropriate for the failure mode. Click Browse if the item you want is not in the table.
Tip: You can exclude a checklist item from the analysis by selecting it and clicking Exclude. Excluded items are gray and italicized.
4.
At the bottom of the Failure Modes table, click the New list and then From Scratch. The Maintenance Action Plan window appears. For example:
The Failure mode reference area displays the unique identifier for the failure mode, which consists of the checklist item’s sequence number and the failure mode number.
5.
To assign the failure mode to another asset in the analysis:
•
Click Change. The Change Asset dialog appears.
•
Browse for an asset and enter a note, if required.
•
Click OK. The dialog closes and the asset number and name are shown in the Asset box.
Tip: You can also change one or more failure mode’s assets on the Strategy Development Analysis window by selecting the Implementation view and the Action Plans tab. Select the failure modes, right-click, and click Change Asset.
6.
In the Failure Mode view, select an unwanted situation from the list. An unwanted situation describes the result of a hazardous scenario such as loss of containment. Examples are “Explosion in venting system” and “Emission of toxic gases”.
7.
Select an inspection regime from the list. An inspection regime refers to government, industry, or corporate standards for safety inspection.
8.
Enter a description in the Failure mode box.
9.
You have the following choices to record failure effects, depending on the tabs displayed:
If the Failure effects box is displayed, describe what happens when the failure mode occurs.
If the analysis supports extended failure effects, select the appropriate tabs and enter information:
•
Local Effects –Local effect on the piece of equipment
•
Intermediate Effects – Intermediate effect on a higher level equipment or asset
•
End Effects – End effect on the asset or system being analyzed
•
Worst-case Effects
Tip: Click to open the Extended Effects dialog.
10.
Select the recommended strategy. The options are:
•
Scheduled restoration/discard: Scheduled restoration entails restoring the initial capability of an existing asset at or before a specified age limit, regardless of its apparent condition at the time. Scheduled discard or replacement tasks entail discarding an asset at or before a specified age limit, regardless of its condition at the time.
•
Condition-based maintenance entails checking for potential failures so that action can be taken to prevent the functional failure or to avoid the consequences of the functional failure. On-condition tasks are so called because the items that are inspected are left in service on the condition that they continue to meet specified performance standards.
•
Failure-finding maintenance involves checking a hidden function at regular intervals to find out whether it has failed. The intervals are calculated based on the required availability of the asset and the reliability of the protected function.
•
Modification/redesign is any one-time change to the equipment, training, maintenance or operating procedures, etc.
•
No scheduled maintenance means assets are left in service until a functional failure occurs, at which point they are repaired or replaced.
•
Review existing maintenance is available for secondary action plans only. This strategy alerts the analysis team to review an asset’s existing maintenance program to identify items that are no longer required.
Note: Review existing maintenance is available only on secondary action plans.
•
Not specified is the default task, and it means that an action type has not been determined.
Tip: Select the Asset History view to see information about the analysis asset’s checksheets, failures, work orders, and work requests. If APM has been configured to access live information in an SAP Plant Maintenance system, you can view the notifications and maintenance orders associated with the analysis asset’s equipment or functional location.
11.
Select the Risk view to perform risk analysis. For more information, see Performing SIF Failure Mode Risk Analysis.
12.
Select the Safety Provisions view to add one or more provisions to reduce the failure mode’s risk level, if required. For more information, see Adding Provisions to a SIF Failure Mode.
13.
Select the Implementation view to develop the recommended action. For more information, see Developing Primary SIF Action Plans and Creating Secondary SIF Action Plans.
14.
Select the Details view, Documents tab to browse for standard documents that are relevant to the analysis.
15.
Select the Details view and tab to apply an action plan status, if appropriate, and see review requests and related root causes. For more information, see Working with SIF Action Plan Task Statuses.
16.
In the Details view, select the Analysis Note tab to add and review the evaluation note.
17.
When you are finished, save and close the failure mode. The failure mode is added to the Info Worksheet tab.