Overview
The following workflow can be used to describe a typical Risk-Based Inspection program. When running risk calculations for the first time, companies are expected to go through these steps to estimate risk and take the appropriate action to mitigate it. The action plan could vary from simply moving to the next step of the process and designing an inspection/mitigation plan to more complex and costly activities such as re-designing the equipment. Once risk has been determined, a Mitigation Plan is designed to ensure the condition of the asset is being tracked through inspection tasks.
The cycle of inspection activities starts once a Mitigation Plan is available. Companies would then start collecting information through inspection activities, with inspectors typically focusing their effort on high-risk items (As informed by the RBI program). This cycle may last for a few years or until a significant event (i.e. a turnaround) takes place, which would allow companies to execute more intrusive inspection tasks. In addition, as new data becomes available through inspection activities, inspectors may recommend the risk analysts to re-run risk calculations to ensure that the plan is still valid, considering changes to the asset condition.
The Risk-Based Inspection Journey can be broken down into two parts:
- Initial RBI Assessment: this part describes the steps to create an initial Mitigation Plan based on historic data
- Evergreen and Reassessment: this part describes the process of continuously updating the risk based on new information acquired from inspection reports and then updating the Mitigation Plan accordingly.
This journey assumes that users have completed the administrator journey and AllAssets has all the basic information available (i.e. Hierarchy, Inspection Templates etc.).
Let’s start with the Initial Risk Assessment.
Initial RBI Assessment
The initial risk assessment for an equipment item is performed in the Risk Analysis application in the RBI Module. As discussed before, if the Hierarchy Template has been mapped to the RBI model, AllAssets will synchronize the data one time from the hierarchy template to the model.
Fields that are required to allow the model to run are marked with a red asterisk “*”. If the user tries to run a model with incomplete information, AllAssets will show an error and it will highlight fields requiring input in red, notifying the user that they must enter those values in order to continue.
Once all required data has been provided, the user can run and then save a risk scenario. There are two types of risk scenarios:
- What if scenario: run risk calculations and show the outcome of the calculations, but Mitigation recommendations will not be generated. A What-if scenario can be used to simulate the impact of new data (e.g. increasing the number of inspections) or determine risk at a future date.
- Driving scenario: a driving scenario will run the risk and create recommendations to be displayed in the Mitigations application. There can only be one current driving scenario per risk component or asset; if risk is ran a second or more time, then the previous driving scenario will be saved a historic scenario.
Users are also able to:
- Attach different types of files to the run using the Media Attachment page (For example, an engineering diagram)
- Review the Inspection History for this particular asset
- Review and open Historical Risk Runs
There are two methods to run the risk calculations:
- Single Risk Run is performed for the one hierarchy item selected by clicking the Run Execute “>” icon on the toolbar. This process will run the risk calculations for this single item.
- Mass Risk Run is performed by clicking the Run Mass Criticality “>>” button on the top right, and will run risk for every item currently visible in the tree / tile control. Mass Risk Run is described in more details in the next section.
One important aspect of risk calculations refers to equipment formed of parents and components. These assets must be run in a specific order so the parent can extract information from the components to determine risk for the parent asset. You can find more information about the right order to run multi-component assets in the Digital Engineering Content section.
At the end of this process, the risk analysts should have the overall criticality and risk ranking for each damage mechanism available. This data will allow users to learn the associated risk with a particular asset and design an appropriate risk mitigation plan. At this stage, the risk analyst may want to run several What-If scenarios to identify opportunities to reduce risk to a reasonable level and to understand future risk, particularly for the next two shutdown inspection opportunities. More drastic measures may also be considered, such as suggesting that the equipment is not fit for purpose. Once all these considerations are made, the risk analyst is expected to design a Mitigation Plan for the asset.
Mass Risk Analysis
As an alternative to running risk for one equipment item, a Mass Criticality Run will run every asset and its associated RBI model that is listed on the tile control. This means Mass Criticality Analysis will create new risk results for each of these items. Every time a driving scenario is run, AllAssets will replace the Active Mitigation plan with a Draft Mitigation Plan. Mass Risk Run will by-pass model validations and ignore errors, so users must be certain the data input of models is of quality.
Mass Criticality Run will check what assets are available in the tree/tile list before running risk calculations. So, users are advised to create a filter and/search for a group of assets before pressing the Mass Criticality Run button. For example, one could use the “Overall Criticality” filter to run Mass Criticality calculations only for the “High” risk items.
At the end of this step, the user should have a risk-ranking for all assets that have a risk model associated with them. This is displayed in a tabular manner and the following information is available:
- Site
- Hierarchy item parent
- Hierarchy item name
- Model overall risk
- Combined CoF (Consequence of Failure)
- Combined PoF (Probability of Failure)
- Inspection priority
If this is the first time the user is running risk calculations, the “With Delta”, Comparison button and Matrix Risk Comparison graph will be empty. However, if previous risk calculations are available, AllAssets will display a comparison between the most recent risk calculations (From the Mass Risk Criticality run) and the previous risk calculations.
Users are also able to print the results from Mass Risk Calculations.
The next step in the process is to create a Mitigation Plan.
Initial Mitigation Planning
Upon completion of the risk run, AllAssets will automatically create Task Recommendations for asset-level models. You can find more information about which models provide Task Recommendations in the Digital Engineering Content section. The user can create, edit and manage mitigation plans at the Mitigations area of the RBI Module.
Once a driving risk run is complete and Task Recommendations are available at the top of the screen, AllAssets will automatically create a draft Mitigation plan – the empty table at the bottom of the screen. This draft plan is empty so users are expected to select the appropriate recommendations to create an Active plan.
Each row on the Recommendations table describes a potential task that can be added to the Draft plan
- Include: This radio button will include the task to the draft plan
- Mechanism: this field describes the damage mechanism which this task is mitigating
- Method: This field describes the method used to mitigate the associated damage mechanism
- Frequency: this field describes how often the task must be performed
- Interval: it should be used with the previous cell and it displays the time unit related to the frequency such as years
- Extent: it describes the extent of the method. For instance, this field could show “100%” which means the asset must be completely inspected. Another example is “Random” which means the inspector is expected to identify specific areas where localized or pitting corrosion is likely to be found
Inspection priority: this value is extremely important. For Baseline RBI models using our 5x5 risk matrix, this value varies from 1 to 25 and it indicates the importance of the recommendation, the lowest the number, the more important the task. - Source: it indicates the source of the recommendation – this is particularly important for multi-component assets that are formed of parents and components where recommendations could be coming from multiple assets. The source does not indicate where to inspect but repeats information from Risk Analysis to show the component that had the governing risk level for the mechanism.
- Override frequency: recommended frequency can be overridden for tasks where this cell is TRUE. Override frequency estimations can come from three sources:
- Recommendations: the frequency value defined by the strategy rules.
- Criticality Half-Life: where data is available to calculate the criticality half-life, AllAssets can override the recommended frequency with an estimate of the remaining half-life of the asset.
- Thickness Half-Life: where thickness data is available and Thickness Reports calculate the thickness remaining life, AllAssets can override the recommended frequency with a calculated remaining half-life of the asset. When thickness data is available then Criticality Half-Life is no longer considered as an override value.
- When Factored Remaining Life (FRL) is turned “on” for the RBI model, AllAssets can override the recommended frequency with a value derived from the FRL settings. The FRL override value may be limited to a maximum value or a value calculated from Criticality Half-Life or Thickness Half-Life where the factor for “half” (i.e. 0.5) is replaced by a factor defined in the Risk Matrix where each box in the matrix can have a different factor.
AllAssets will follow this order when trying to override the frequency.
The radio button on the left-hand side of the Recommendations table can be used to move tasks from the Recommendations table to the Draft Plan. In addition to Task Recommendations, users can add Ad-hoc tasks. These ad-hoc tasks are described by:
- Mechanism
- Method
- Inspection Priority
- Extent
- Due Date
Once all the recommendations have been moved to the Draft plan, users can edit Tasks by clicking on the edit button in the first column. Users can also add new information such as location, availability, preparation and some specific commentary around the task. All these fields are optional.
On this page, users can also attach files using the Media Attachment button and check previous plans.
The final step in the process is to activate the plan. By activating the plan, users are effectively approving the Mitigation Plan for the asset and all the fields will be locked-up until a new driving risk scenario is saved or the user clicks the button that swaps between the Active and Draft plans.
Evergreen RBI - Update Risk Assessment and Mitigation Plan
Updating the risk calculations and recommendations is an essential part of the RBI Program. One of the most important resources in the evergreen process is the inspection/thickness reports created as part of the previous inspection planning – this journey is described in more details at the IDMS journey.
The following section details the critical steps in the process of updating risk calculations. These steps are accompanied by a description of where to find the information in AllAssets.
Most of the information required to update risk assessments can be found in the Asset Hub. To access the Asset Hub, the risk analysts must navigate to the Hierarchy area of the Manage Equipment Module. Every asset that has a Risk-Based Inspection model associated with it will have access to the Asset Hub.
Moreover, data can also be collected and processed in reports. AllAssets offer two options to extract information from the platform – the Report area, which is accessible from the Manage Equipment module and PowerBI.
The following reports are available in AllAssets:
- Combined Report
- Datasheets
- Inspection Reports
- Mitigation Plans
- RBI
- Thickness Locations
- Thickness Reports
You can find more details around these reports by clicking here.
AllAssets data can be accessed by PowerBI and it gives users to ability to create dashboards from the available data. For more information about Report Builder and PowerBI, please see section XXX>
Now, let’s move into the most relevant information to update risk.
Inspection Data
As discussed, data emerging from previous inspections is one of the most important pieces of information for in-service equipment already in the RBI program. These inspection activities have been assigned to specific assets to address potential damage mechanisms so the outcome of these inspection activities will bring a wealth of information to update the risk calculations.
All the raw information for Inspection and Thickness Reports can be found at the IDMS module in AllAssets.
The Asset Hub offers an overview of the thickness data which can be used as another source of information for risk calculations as well as hyperlinks to the most recent inspection and thickness reports.
Data Analysis
The Risk Analyst must process data to create the following information:
- Number and Confidence of Inspections: Inspection confidence is a measure of the ability of the actual inspection method to accurately assess a particular damage mechanism and its level or rate of damage. A combined number and confidence of inspections must be entered individually for the following damage mechanisms: Internal Corrosion, External Corrosion, Environmental Cracking and Creep. The inspection confidence can be found in each Inspection and Thickness Report. The Reporting module allows users to download reports for many assets.
- Last Inspection Date: The Last Inspection Date must be entered individually for the following damage mechanisms: Internal Corrosion, External Corrosion, Environmental Cracking and Creep.
- External Date in Service: Confirm the External Date in Service if the external protective coating was renewed since the previous Risk Analysis.
- Environmental Cracking Damage at Last Inspection: Review cracking inspection reports to determine whether Environmental Cracking was confirmed in the most recent cracking inspection.
- Corrosion Rate: Review the maximum and average corrosion rates in the latest Thickness Report as well as the Asset Hub and determine whether the corrosion rate needs to be changed.
In addition to the above, the following input data are critical for the Risk-Based Inspection Model so it is really important to keep them up to date. Any changes in the values of critical input data should be reviewed, and the risk should be reassessed:
Table 2: Critical Input Data for RBI Models
RBI-Critical Variable | Description |
Corrosion rate | The rate of wall thickness reduction influences the ability of an equipment item to sustain its intended purpose of pressure containment. The internal corrosion rate is developed for the current service of the item and the external corrosion rate is developed for external conditions. |
Age of equipment item | The time duration of an item in its current service (typically based on installation date or date placed in current service). |
Original thickness of equipment item | The thickness of the item at the start of its current service. |
Other damage mechanisms | The additional damage mechanisms beyond corrosion and environmental cracking considered in the RBI assessment for an item. |
Cracking Damage Found at Last Inspection | A true/false condition representing the existence of a known active crack at the previous inspection. |
Operating pressure | The predominant pressure of the item during the mode of operation assumed in the RBI assessment, typically normal, steady-state operating pressure. An increase greater than 10 psig warrants re-review. |
Operating temperature | The predominant temperature of the item during the mode of operation assumed in the RBI assessment, typically normal, steady-state operating temperature. An increase greater than 25°F warrants re-review. |
Representative Fluid | The fluid selected to represent the predominant fluid available for release from a specific equipment item. |
Concentration of toxic fluid in a mixture | The weight-per cent of toxic fluid in a mixture with a non-toxic fluid. As a general guideline, an increase greater than 10% warrants re-review. |
Fluid phase | Input as either a liquid or a gas in RBI, this value reflects the predominant phase of fluid at the operating conditions associated with the assigned deterioration rate, pressure, and temperature. |
Companies may also agree on other variables being critical, it is important to register what variables must be reviewed in every reassessment cycle.
Risk Analysis
With the above information, new risk calculations can be performed to help prioritize and focus the inspection efforts for equipment. The new information must be added individually to each asset’s Risk model at the Risk Analysis area of the RBI Module. Once the risk calculations are completed, a new risk ranking will be available – the risk analyst is expected to assess the results and check whether the risk is at an acceptable level. If the risk is not at an acceptable level, the risk analyst is expected to investigate options to reduce risk to as low as reasonably practicable. This investigation may require the analyst to run What-if scenarios to understand how certain variables are impacting risk calculations and to understand future risk. Once the risk is understood, the next step in the process is creating a mitigation plan.
Mitigation Planning
A new Mitigation Plan is developed to identify the types, amounts, and frequency of inspections that should be performed to manage the updated risks and ensure the integrity of each equipment item.
These plans are created and managed in AllAssets at the Mitigation Plan.