Defining Barriers (LOPA)

Barriers, copied from the Consequence’s associated HAZOP, will show here. These will be indicated with an.

If applicable you can create more Barrier or change the existing ones (the changes will be synced back to the HAZOP).

The Initiating Event Frequencies and the Barrier PFDs that you defined, will be used to calculate the SIL levels for the Consequence Categories. This can then be used to assess if the adequacy of the LOPA’s defined Barriers and if a SIF is needed.

Creating and defining Barriers

To create and define a Barrier:

• Click the +Add Barrier button.
• Click the fold-out bar to open the Barrier Properties.
  Click the fold-out bar.
• To use already defined PFD data from the IMS database, click From Existing to use a Barrier already used in another LOPA, or click From Template to create a Barrier from a template. Note: If you add From Exiting a copy will be created, i.e., Barriers will not be shared between LOPAs.
• A popup will open. Search for and select the appropriate Exiting Barrier or Template Barrier (or click + to create a new Barrier / Template).
• Review the properties: PFD Low and PFD High.
• Click OK (or Cancel) to close the popup.
• Add a Description.
• Select the Type (Control Barrier, Recovery Measure, or Conditional Modifier).
• Search for and select Safety Critical Elements (SCEs) / Equipment if applicable. Note: These are summarized on the Safety Critical Elements Tab .
• Select the Category (e.g., BPCS).
• When done, click X to close the fold-out.
• Select the applicable Consequence Categories (People (P), Asset (A), Community (C), Environment (E)). Take Note that applicable Categories should be highlighted in blue.

Select the applicable Consequence Categories. 

• You can specify that a Barrier is Valid (green),  Partially Valid (PV) (yellow), or Not Valid (NV) (white) for a specific Initiating Event.

Click the button to make the Barrier Valid / Partially Valid / Not Valid for an Initiating Event. 

• Click the document buttons to write a Justifications (per Initiating Event).
  Click the document buttons to write a Justifications (per Initiating Event).

It is also possible to not use a Template or an Existing Barrier. In this case you should edit the card description and the PFD as well:

• Edit the Barrier’s description by just clicking on the card (i.e., select the card) and start typing.
  To edit the description, just click on the card (i.e., select the card) and start typing.
   
• Click in the L and H section of the PFD and change the values. Note: If you are not defining PFD as a range, enter the same value in both L and H fields.

Adding / Deleting / Merging

Use the Toolbar or Shortcut keys to Add / Delete / Merge Barriers.