What is Asset Criticality Ranking? The Complete Guide

If you are familiar with a Master Equipment List (MEL), you know that it can be extensive, sometimes including tens of thousands of functional locations. In such cases, how do you determine where to focus your maintenance efforts and resource allocation?

This is where Asset Criticality Ranking (ACR) comes into play. A well-structured criticality ranking system provides a data-driven approach to prioritizing preventive maintenance, planning, and asset management activities, ensuring that resources are directed to the most important assets.

What Is Asset Criticality Ranking?

Imagine asking a boiler area manager about the most critical piece of equipment in a facility. The answer would likely be “the boiler.” But if you ask the same question to a paper machine area manager, they might say “the Fourdrinier bed” or “the couch roller.”

Both answers seem correct, but only from their respective perspectives.

At this stage, criticality is based on perception and experience, often leading to subjective decision-making.

The goal of an asset criticality assessment is to eliminate this subjectivity by applying objective, standardized criteria to evaluate and quantify asset importance.

Once the criticality assessment is completed, assets such as the boiler and couch roller will likely rank high in the hierarchy, but their placement will be justified with clear, documented reasoning rather than personal opinions.

In essence, a criticality analysis is a structured methodology that objectively quantifies the importance of assets within an operation.

Why Does Asset Criticality Ranking Matter?

Implementing Asset Criticality Ranking offers multiple benefits:

• Optimized Maintenance Prioritization: By identifying high-priority assets, organizations can ensure that critical equipment receives the necessary attention to prevent failures and unplanned downtime.
• Efficient Resource Allocation: Maintenance teams can focus their efforts on the most impactful assets, avoiding unnecessary work on less critical components.
• Improved Risk Management: Understanding asset criticality allows organizations to assess potential risks and implement mitigation strategies.
• Proactive Maintenance Strategies: Highly critical assets can be managed using preventive maintenance and condition monitoring, reducing the likelihood of failures and improving overall reliability.
• Increased Operational Efficiency: A well-structured ACR ensures that maintenance decisions align with the broader operational and financial objectives of the organization.

Asset Criticality Criteria

When conducting a criticality analysis, assets are evaluated based on five key criteria: Maintenance, Operation ($), Environment, Safety, and Quality. Each criteria includes specifics that help assess the importance of an asset within the overall process.

1. Maintenance

This category focuses on the asset’s reliability, maintainability, and the effort required to keep it operational and complete the related work order. Key criteria include:

• Failure Frequency:  How often does the asset fail, and based on failure modes, what is the impact on maintenance resources?
• Ease of Repair: The complexity and time required to restore the asset to full functionality.
• Spare Parts Availability: The lead time and cost of acquiring necessary spare parts.
• Preventive and Predictive Maintenance Needs: The level of ongoing maintenance required to prevent unexpected failures.

2. Operation ($)

This category evaluates the financial impact of asset failures and downtime. Key criteria include:

• Impact on Production Throughput: How much does the asset influence production output?
• Cost of Downtime: The financial loss incurred when the asset is non-operational.
• Energy Consumption: The efficiency of the asset and its effect on operational costs.
• Operational Dependency: How critical the asset is to other production processes and dependencies.

3. Environment

This category assesses the asset’s impact on environmental sustainability and regulatory compliance. Key criteria include:

• Environmental Risks: Potential for spills, leaks, or emissions that could harm the environment.
• Regulatory Compliance: Adherence to local and international environmental regulations.
• Waste Generation: The amount of waste or byproducts generated and their disposal impact.
• Energy Efficiency: The asset’s contribution to sustainability and carbon footprint reduction.

4. Safety

This category focuses on risks assessment to personnel and workplace safety. Key criteria include:

• Hazard Potential: The likelihood of accidents, fires, or hazardous material exposure.
• Impact on Personnel Safety: The potential consequences of asset failure on worker health and safety.
• Compliance with Safety Standards: Adherence to OSHA, ISO, or other industry-specific safety regulations.
• Emergency Preparedness: The ability to quickly respond and mitigate risks in case of failure.

5. Quality

This category ensures that asset performance aligns with product quality and customer satisfaction. Key criteria include:

• Impact on Product Quality: How asset performance affects the consistency and standards of final products.
• Process Stability: The asset’s role in maintaining operational consistency and reducing variability.
• Defect Prevention: The asset’s ability to minimize scrap, rework, and product defects.
• Compliance with Industry Standards: Adherence to quality control and certification requirements.

By incorporating these detailed criteria into the Asset Criticality Ranking process, organizations can ensure a comprehensive, data-driven evaluation of their assets.

The Outcome of Asset Criticality Ranking

Once the scope and ranking criteria have been established, each asset is assigned a criticality score within the asset hierarchy.

Example: ACR in a Tissue Plant Converting Section

Maintaining a well-balanced ranking process is crucial to ensuring an accurate and meaningful assessment of asset criticality. If, at the end of the evaluation, nearly half of all assets are classified as Criticality A, this may indicate that the ranking criteria are either too broad or not well-defined, leading to an overestimation of asset criticality.

Final Thoughts

Whether you’re managing large or small asset inventories, implementing an Asset Criticality Ranking (ACR) process is essential for making informed maintenance decisions. By moving away from subjective assessments and applying a structured, data-driven approach, companies can accurately determine which assets require the most attention. This ensures that maintenance efforts are aligned with operational priorities, reducing the risk of unexpected failures and optimizing resource allocation.

A well-defined ACR process helps prevent overclassification of assets and ensures that critical equipment is properly identified based on its impact on operations. Over time, this approach leads to more effective maintenance planning, reduced downtime, and improved asset reliability.

Investing in a clear and structured ACR methodology today provides long-term benefits by creating a maintenance program that is both efficient and sustainable.

Raphael Tremblay,
Spartakus Technologies
[email protected]