A combination of maintenance strategies and techniques is needed for optimal maintenance management. Due to tight budgets and limited resources, maintenance departments must be methodical about how and when to perform maintenance activities. That’s where risk-based maintenance comes in.

A maintenance technician using a gauge to monitor machinery and assess risk as part of risk-based maintenance.

What is Risk-based Maintenance?

Risk-based maintenance (RbM) is a well-known maintenance methodology that uses risk assessment principles to prioritize maintenance work and optimize the allocation of maintenance resources. Assets that carry the most risk if they fail are prioritized first, down to the assets that carry the least amount of risk if they fail, which are prioritized last. Risk-based maintenance focuses on using maintenance resources (supplies, personnel, and time) economically.

Assets that may be high risk and top priority in risk-based maintenance will vary by industry and each individual organization. Just a few examples include:

  • Major building systems in facility environments (lighting, electrical, HVAC, plumbing)
  • Vital production line machines in manufacturing environments
  • Infrastructural equipment in the construction industry
  • Large trucks used to transport goods in the fleet industry

Why Risk-based Maintenance is Important

Risk-based maintenance, in part, involves preventive maintenance, which is important for multiple reasons. This methodology helps to define problems with assets before they happen. Corrective maintenance carries high overhead and inventory costs and results in more unplanned downtime. The work also takes longer since the problem is diagnosed at the time the maintenance job is carried out. Planning more preventive maintenance avoids corrective, or reactive, maintenance. There is less machine downtime when maintenance work is scheduled ahead of time.

Using a risk-based maintenance method can also improve the safety of equipment, and breakdowns will occur less often. The goal is to extend the lifecycle of assets. With less equipment failures happening, risk-based maintenance can also improve the reputation of organizations because customer’s supply chain issues are reduced.

Developing Strategies Using Risk-based Maintenance

For organizations that don’t already use a risk-based maintenance approach but want to start doing so, there is some planning that should take place beforehand, which will help to better optimize maintenance strategies.

Step 1: Identify All Assets

The first step in using a risk-based maintenance methodology is to identify all maintainable assets owned by the organization. How many there are, the asset ages, what they are used for, how often they are used, their costs. This information can be easily recorded and stored in computerized maintenance management system (CMMS) software.

Step 2: Criticality Analysis

The next step is to complete criticality analysis, an essential part of overall risk analysis. In this process, assets are given a rating of criticality based on potential risk. Part of a larger Failure Modes and Effects Analysis (FMECA), which we will discuss more later on in this article, criticality analysis makes sure that a genuine risk-based point of view is taken when determining asset reliability. It also helps to determine the monetary costs of each type of failure for each asset. Using historical data from a CMMS system will assist the maintenance department in making objective decisions.

A critical asset that would rank high priority during risk-bases maintenance planning.

There are two common ways to perform criticality analysis. The first is by using a 6×6 grid. The severity of each consequence is plotted against the probability of occurring, as well as the monetary costs of each consequence or failure happening. The grid provides a color-code corresponding to the severity and probability of failure – green for low, yellow for medium, and red for high.

The second way to conduct criticality analysis is by labeling risks by category, then listing each asset and ranking the severity of failure in each category based on that risk from 1-10. The numbers in each risk category for each asset are multiplied together to get the asset’s Risk Priority Number (RPN). After that, the RPNs can be ranked to determine groups of equipment that are extreme, high, medium, low, or no risk. The criticality analysis process will help make risk-based maintenance decisions easier.

Step 3: Risk Assessment

After assets have been identified and criticality analysis has been done, using a risk-based maintenance methodology continues by applying multiple risk assessment techniques. Consider all of the things that could go wrong by doing FMEA or another method of asset risk assessment. This includes multiple types of risk that impact asset systems, individual asset lifecycles, resource, and risks associated with breakdowns. Carrying out an in-depth risk assessment process can help with components of reliability planning such as having enough spare parts in stock and handling valuable plant redundancy. Determine factors like: Which assets are high risk and which are not? How severe are the risks if the asset fails?

Asset Systems Risks

The risk assessment framework should be applied to each system within a facility. For example, the fire management system should be considered, and questions such as the following should be asked. Will the sprinklers turn on if there is smoke or flames present? Will the notifications to start work on repairs of this system be activated when needed? Are the fire extinguishers full and accessible? Do the building’s visual and auditory alarms work?

Other systems of assets that can be evaluated for risk include the HVAC and plumbing systems. Ask questions like those above that apply to those assets. A production environment would look at series of operations that create a production cell, or a complete production line for raw materials. Fleet companies would analyze how each of their vehicle types work and determine the risks if each type failed.

Asset Lifecycle Risks

Questions to ask to determine asset lifecycle risks include: How many assets are very old and have a short remaining useful life? What will it cost to purchase replacements? Which assets should be run to failure?

Resource-based Risks

Resource-based risks revolve around answers to questions such as: Is the organization having to do more work with less employees as time goes on? Is there enough staff to do proper preventive maintenance (PM) regularly?

Breakdown-based Risks

Lastly, breakdown-based risks can be assessed by answering questions like: What is the average repair cost for each type of asset? How much downtime or lost production is occurring because of certain machines breaking down or malfunctioning? Have there been any accidents or safety hazards that occurred as a result of specific assets breaking down?

Step 4: Create an Inspection Plan

The fourth step in implementing risk-based maintenance methodology is to plan the frequency and type of asset inspections. A risk-based inspection, derived from completing criticality analysis, should be done frequently on machines and vehicles that will jeopardize production or transport of goods if they break down. Inspections for assets with moderate risk upon failure, for instance, would be labeled in computerized maintenance management system (CMMS) software as one type of preventive maintenance work order.

Step 5: Propose Mitigation

After risks have been evaluated and ranked and an inspection plan is made, a proposal for mitigating risks should occur next. This may be complex and take some time to complete, but it should be thoroughly applied to every type of risk and all maintainable assets. Inspections for assets that pose the greatest risk if they fail should follow condition-based maintenance principles and be scheduled as such. It’s a good idea to create templates that can be used over and over again to ensure consistency in the process and save the time it would take to manually write out instructions.

Risk mitigation plans can always be expanded on or modified as new assets are purchased or additional risks are uncovered. There is no set format or requirements for the mitigation plan as it largely depends on the organization’s industry, size, and maintenance needs.

Read more about how to mitigate risks: Keeping Assets Healthy: A Complete Guide to 4 Types of Maintenance.

Step 6: Reassess

Lastly, you should reassess your risk-based maintenance method before finalizing it. A team can be assigned to review the information and propose any changes or additions to upper management. Once this step is complete, you are ready to begin incorporating this maintenance methodology into your maintenance program.

Advantages of Risk-based Maintenance

Risk-based maintenance works well in numerous scenarios, but here are a few examples. If an organization and its infrastructure rely on expensive machinery to accomplish production work, applying risk-based maintenance concepts will work well within a maintenance plan. If maintenance managers are new to building a preventive maintenance plan, developing and applying a risk-based maintenance methodology can be the foundation for creating a more robust maintenance program. Finally, if you have limited resources to work with, RbM can be a good way to evenly spread out preventive maintenance work.

Performing maintenance based on a risk-based maintenance method costs less than performing too much preventive maintenance. RbM also allows limited resources to be allocated more effectively. Risk-based maintenance puts the maintenance team in a mindset where they will carefully consider what type of maintenance to perform and when, based on the criticality of the asset and severity of the repair that is needed. Finally, this maintenance methodology requires little-to-no planning in the long term once the RbM parameters have been set. Unnecessary work orders that bog down the software system and maintenance schedule are reduced.

Disadvantages of Risk-based Maintenance

One disadvantage of risk-based maintenance is that it does take some significant initial planning. If organizations don’t have the time and personnel to dedicate to proper planning, this method will not be successful.

Another disadvantage is that asset risk assessment will need to be updated periodically. For example, as an essential machine ages, the risks associated with it breaking down increase. If this information is not updated regularly, organizations run the risk of encountering unexpected problems.

Finally, using a risk-based maintenance method creates more complexity within the maintenance strategy, which not all maintenance departments have the resources to manage.

Lower your Risk of Asset Failure with FTMaintenance

Risk-based maintenance methods can be implemented or improved upon with CMMS software such as FTMaintenance. Request a demo today to learn more about how FTMaintenance can assist you with risk-based maintenance.

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