IOW Main Screen

Updated on 09 Aug 2024
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To see the list of registered IOWs (Integrity Operating Windows):

Go to the IMS Main Menu.
Click IOW to go to the IOW Main Screen (Grid List).

A screenshot of a social media post Description automatically generated Click on the IOW Main menu, to list all IOWs.

Use the scoping bar, the filter, or the search functionality to list the desired IOWs.
Find IOWs using the scoping bar / filter / search functionality.
If desired, expand or collapse an IOW record using respectively the and button in the record row. This will give you a list of all Barriers connected to selected IOW, and registered Concerns from the IOW Details Page.
The IOW Main Screen, showing one record expanded.
Each record shows several fields, summarizing the IOWs (see the table below). To see more, click on the Settings icon in the toolbar and add additional fields.

Click on the settings icon to modify the grid.

IOW Record

Data in the IOW record:

Column Name	Description
Active	Shows whether the IOW is active or inactive. A green bar means the IOW is active, a grey bar means it is inactive.
IOW ID	Unique identifier for the IOW, to be populated when creating a new IOW.
Corrosion Loop Name	For PEI: Name / short description for the CL to which the IOW is linked, to be populated when creating a new Loop.
Corrosion Loop Number	For PEI: Unique identifier for the CL to which the IOW is linked, to be populated when creating a new Loop.
System Name	For PLSS: A Unique name for the System to which the IOW is linked, to be populated when creating a new System.
Variable	The key parameter to be monitored. Note 1: The available key parameters that can be selected for your variable will depend on the list that has been defined in the IOW Settings. Note 2: When you don't want to link to a single PI Tag, but rather create a Virtual Tag, you must select the Variable "Virtual Tag" when the IOW is being created, this will then show here.
Measurement Group	The Measurement group is based on the configuration of the IOW Variable in Settings \ Maintenance \ RBI Specific data \ Variable - IOW. Here the Measurement group is a mandatory field.
Measurement Unit	The variable's measurement unit. Note: If the Measurement unit differs from the PI Engineering Unit a warning will show here.
PI/Virtual Tag	The linked PI Tag name, or defined Virtual Tag.
PI Status	This shows the status of the PI Tag. Below is shown the best to the worst status: Interfaced with PI and connected to Barrier Connect to Barrier. Note: This means it is interfaced with PI Service, but not yet connected to a Barrier. Not Interfaced with PI Service. Fill in Recommended Fields.
Expression	Either the Virtual Tag's Expression or the PI Tag's description will show here.
Value	The current value of the reading or Virtual Tag calculation
Measurement Location	The variable (tag name) location is a unique identifier associated with the information collection system used to acquire the measurement.
Target Min	The (ESP) Target range(s) (previously called "Actual min/max") specify the operating range(s) (see Integrity Operating Windows (IOWs) - Theory) for a variable and are related to economic optimization or the reliability of unit operations. Note: This column is hidden by default. To add go to settings.
Target Max	See Target Min.
Integrity Min	The Integrity Min and Integrity Max specify the ESP Integrity/Standard limits (see Integrity Operating Windows (IOWs) - Theory). These are specifically for RBI "Integrity min/max" – one that, if exceeded over time, could cause one of the following to occur: A release of hydrocarbon(s) (loss of containment), a non-orderly shutdown, or a negative impact in the long term.
Integrity Max	See Integrity Min above.
Measurement freq.	The Measurement frequency specifies how often the measurement should be made. Note: IMS will align the CL’s IOW frequencies. The PI data for all IOWs will be collected at the fastest of these frequencies.
RWC	The Responsible Work Centre in the proactive monitoring work process. Who is responsible for this to be executed?
Limit Type	This is an optional Limit Type that can be specified for the IOW.
Limit Classification	Critical / Standard / Monitoring.
Maximum time single exceedance	This is the time that the target or integrity min or max values are in a single continuous exceedance (since the last barrier status change) for which IMS will trigger a red (integrity) or orange (target) indicator status on the linked Barrier in the CL. Intervals are shown in days:hours:minutes format. Note: The Max time single exceedance, and/or Max time cumulative exceedance, and/or Max nr of exceedances allowed must be specified in order for IMS to determine a Barrier status for the IOW.
Maximum time cumulative exceedance	This is the total time that the target or integrity min or max values have been in exceedance (since the last barrier status change) for which IMS will trigger a red(integrity) or orange(target) indicator status on the linked Barrier in the CL. Intervals are shown in days:hours:minutes format. Note: The Max time single exceedance, and/or Max time cumulative exceedance, and/or Max nr of exceedances allowed must be specified in order for IMS to determine a Barrier status for the IOW.
Maximum nr. of exceedances allowed	This is the number of times the variable can go into exceedance for which IMS will trigger an orange indicator status on the linked Barrier in the CL. Note: The Max time single exceedance, and/or Max time cumulative exceedance, and/or Max nr of exceedances allowed must be specified in order for IMS to determine a Barrier status for the IOW.
Nr Exceedances	The number of exceedances measured by IMS.
Nr Exceedances last three months	The number of exceedances in the last three months measured by IMS.
Nr Exceedances last year	The number of exceedances in the last year measured by IMS.
Last Exceedance Date	The last exceedance date as determined by IMS.
Criticality Rating	The driving Criticality result from all Components and Sub-Components assigned to the CL.
Labels	User assigned labels will show here.

Measurement Frequency

Consider the following when determining how often IOW variables must be measured:

For discrete measurements (non-continuous) like samples, the frequency should be based on an ESP philosophy, e.g.,
- The time frame in which the variable can deviate, and
- The severity of potential damage. Note: the severity also determines the priority of the variable (critical, standard, monitoring).
For proactive monitoring, the monitoring frequency should be determined based on:
- The rate of possible change in variable (e.g., temperature can change in hours, Amine strength in weeks); and
- The resulting damage rate when operating outside window (slightly increased corrosion rate versus rapid cracking).

IOW Limit Classification

Furthermore, as part of the IOW definition, the limits should be classified as either Critical (C), Standard (S) or Monitoring (M).

Critical Limit (C) – Critical limits are set for IOW parameters that when exceeded pose an immediate threat to Equipment integrity and as such should be immediately followed up by Operations. These typically rank in S-RBI criticality classes as High or Extreme. Clear mitigating measures and reporting requirements should be readily available to the (panel) operator. These parameters should be available as critical alarms in a master alarm database and are usually also part of Process Safeguarding and trigger instrumented trip functions. Example: Minimum flow to furnaces, pH as indicator for a caustic soda breakthrough and temperature limits to prevent chloride stress corrosion cracking.
Standard Limit (S) – Standard limits are set for parameters that when exceeded have a short to mid-term effect (i.e., effects are noticeable within days to months). These typically rank in S-RBI criticality class as Medium or Medium-High. Examples are chloride content of sour water streams, CO₂ and/or H₂S loading of amine/solvent at the Absorber and oxygen content of BFW. These parameters need to be closely monitored and with a mitigating action priority dictated by the expected time to reach the minimum required integrity level.
Monitoring Limit (M)* – Monitoring limits are set for parameters that when exceeded have a long-term effect (i.e., effects are noticeable in months to years) and where long-term exceedance would not change the overall S-RBI criticality class. These typically rank in S-RBI criticality class as Low or Negligible. Operations staff should intervene to bring the limit within the window. Intervention, if required, is initiated by Support staff (e.g., corrosion engineer). Examples are Sulphur content in crudes, heat-stable salts content in amine streams, and catalyst fines (ash) content in the Catalytic Cracker Unit slurry stream. These parameters need to be monitored to detect unfavorable trends and manage the long-term integrity of the Equipment. To provide clarity, Monitoring Limits should be treated as Target Limits with respect to communicating operator response. *Note: The ESP equivalent for Monitoring-only variables is “Target”.

There are several shortcuts or available features that the IOW toolbar can be used for. These are all explained in IMS Main Screen (Grid List).

Filtering IOWs

From the IOW overview page, several filters can be used to drill down the search results for the shown list of IOWs.

To filter a list:

Click on the filter button.
Check the filters that you want to use.
Click Show ….

Click the filter button and select the desired filters.

For more information on using filters see IMS Main Screen (Grid List).

The range filters can be used as shown below.

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Using Range filters.

Example: Below filter criteria returned 1 IOW that has: at least one record with Target Exceedance % between 5% and 30%, an integrity Exceedance greater than 5%, and an Average Target Exceedance lower than 80%, as shown in the PI Exceedance grid in the IOW details.