The Ultimate EHI Review Checklist Template: A Guide to Asset Health

Why Your EHI Review Needs a Template

Creating an EHI review from scratch every time? That's a recipe for inconsistency, missed details, and ultimately, less effective insights. A template provides a structured framework, ensuring that every review covers the essential areas and follows a repeatable process. Think of it as a checklist for your checklist.

Here's why a template isn't just helpful; it's necessary:

• Consistency: Guarantee a standardized review process across all assets, regardless of who's conducting it.
• Efficiency: Save time and effort by eliminating the need to reinvent the wheel each review cycle.
• Reduced Errors: Minimize the risk of overlooking crucial data points or neglecting important analysis steps.
• Training Aid: Provide a clear and concise guide for new team members or those unfamiliar with the EHI review process.
• Improved Documentation: Facilitate thorough and well-organized record-keeping for future reference and audits.
• Continuous Improvement: Provide a baseline to benchmark performance and identify areas for optimization in your condition monitoring program.

A good template shouldn't be rigid, but rather a flexible starting point that can be customized to reflect your specific equipment and operational context.

Understanding the Key Components of an EHI

An Equipment Health Index (EHI) isn't just a single number; it's a carefully constructed composite of data from various condition monitoring techniques. Understanding the individual components that contribute to your EHI is critical for accurate interpretation and effective action. Let's break down the most common and impactful elements:

• Vibration Severity: This component often carries significant weight, as vibration is a leading indicator of mechanical degradation. It's usually derived from vibration analysis data, quantifying the overall severity of vibration patterns (e.g., using RMS velocity or a customized scoring system). Higher values generally indicate more significant issues.
• Lubricant Condition: Represented by parameters such as viscosity, particle count (ferrous density, silica content), and oil oxidation. Deterioration in lubricant quality signifies increased wear and potential damage to internal components.
• Thermographic Signature: An assessment of temperature variations across the asset. Excessive or localized hot spots frequently point to friction, misalignment, or failing electrical connections.
• Ultrasonic Emission Intensity: This component quantifies the level of ultrasonic emissions, which can indicate leaks, friction, and impact events. Increased emissions often signal the onset of failure.
• Process Parameter Deviations: How far are key process variables (pressure, flow, temperature) deviating from their expected range? Significant deviations can impact equipment health.
• Electrical Signature Analysis (for electric motors): Includes parameters like motor current signature analysis (MCSA) and insulation resistance measurements. It's a vital component for electric motor driven equipment.
• Trending Rate of Change: It's not just about the current value, but how quickly a parameter is changing. A rapidly deteriorating trend is a more immediate concern than a consistently high value.

Each of these components can be weighted differently within the overall EHI calculation, based on their relative importance to the specific equipment and the potential consequences of failure.

Performance & Trending Analysis

This section focuses on the "big picture" - understanding the overall health of your equipment and how it's changing over time. It's where you move beyond individual data points and start seeing patterns. Here's a framework for your Performance & Trending analysis:

1. Baseline Establishment & Current Score:

• Record the Current EHI Score: Clearly document the latest EHI value.
• Compare to Baseline: Refer back to the established baseline EHI score (typically set during commissioning or after a period of stable operation). Note the difference - is it within acceptable tolerance levels?
• Define Acceptable Range: If you haven't already, define the acceptable range for your EHI score based on historical data and equipment criticality. This helps flag potential issues before they become critical.

2. Trend Visualization & Interpretation:

• Plot the Trend: Create a simple graph displaying the EHI score over time (weekly, monthly, quarterly - choose the appropriate interval). X-axis: Time; Y-axis: EHI Score.
• Identify Trends: Visually inspect the trend line. Is it:
  • Improving: Positive sign! Investigate what's driving the improvement and look for opportunities to replicate those actions.
  • Declining: Significant concern! Trigger a deeper dive into the contributing factors (see subsequent sections).
  • Stable: Generally positive, but still requires monitoring for subtle shifts.
• Calculate Rate of Change: Determine the rate of change (e.g., EHI score per month) to quantify the trend's severity.
• Note Significant Deviations: Highlight any points on the graph that deviate significantly from the established trend. Document the date, EHI score, and a preliminary explanation for the deviation.

3. Peer Comparison (If Applicable):

• Identify Similar Assets: Select a group of assets considered functionally similar (same model, usage profile, operating conditions).
• Compare EHI Scores: Compare the subject asset's EHI score to the average or median score of the peer group. A score significantly lower than the peer group is a red flag.
• Analyze Discrepancies: If discrepancies exist, investigate the underlying causes. Are there differences in maintenance practices, operating conditions, or equipment age?

Template Checklist for Performance & Trending Analysis:

• Recorded current EHI score.
• Compared current score to baseline.
• Verified score is within acceptable range.
• Plotted EHI trend over time.
• Identified trend (improving, declining, stable).
• Calculated rate of change (if applicable).
• Noted significant deviations from trend.
• Performed peer comparison (if applicable).

Condition Monitoring Data Review

This section focuses on the detailed review of data generated from your condition monitoring techniques. It's not enough to simply collect data; you need a structured process for analyzing it and identifying trends. This template provides a framework for ensuring a thorough and consistent review.

For Each Condition Monitoring Technique (Vibration Analysis, Oil Analysis, Thermography, Ultrasonic Testing, etc.):

1. Date and Time of Data Acquisition: Document when the data was collected. This is crucial for correlating data with operational events.
2. Equipment ID and Location: Clearly identify the specific asset the data represents.
3. Data Collector/Technician: Record who acquired the data. This allows for accountability and provides a point of contact for questions.
4. Baseline Comparison: Compare current data to established baseline values. Note any deviations and quantify the difference (e.g., Vibration amplitude 15% higher than baseline).
5. Trend Analysis: Plot data over time to identify trends. Use control charts or other statistical tools to highlight significant changes. Look for patterns that might indicate a developing problem.
6. Anomaly Detection: Specifically note any anomalies - unusual readings, unexpected patterns, or anything that deviates from the expected behavior.
7. Root Cause Assessment (Preliminary): Based on the data, what are the possible root causes of the observed anomalies? Document potential causes, even if they are speculative at this stage.
8. Recommended Actions: Outline the next steps to be taken. This might include further investigation, adjustments to maintenance schedules, or escalation to a reliability engineer. Be specific and assign responsibility for the action.
9. Reviewer Comments & Signature: The reviewer should add comments summarizing their findings, justifying any recommended actions, and providing their signature to confirm the review.

Example Table Format for Review:

Date	Equipment ID	Parameter	Baseline Value	Current Value	Trend	Anomaly?	Possible Cause	Recommended Action	Reviewer
2024-10-27	Pump-001	Vibration (Hz)	2.0 in/s	2.8 in/s	Increasing	Yes	Bearing wear?	Schedule vibration analysis and inspect bearing	John Smith
2024-10-27	Motor-002	Oil Viscosity (cP)	15	16	Slight increase	No	Normal fluctuation	Monitor next oil sample	Jane Doe

Vibration Analysis Checklist

This section focuses on the critical steps for a thorough vibration analysis review. Remember, consistent and accurate data collection is paramount.

1. Data Acquisition Verification:

• Sensor Placement: Confirm sensors are positioned correctly according to manufacturer guidelines and asset-specific procedures (e.g., 90-degree phase monitoring, horizontal/vertical axis). Document any deviations.
• Sensor Calibration: Verify sensor calibration dates and ensure sensors are within their calibration window. Record calibration certificates.
• Data Acquisition System (DAS) Settings: Confirm DAS sampling rate, resolution, and trigger settings are appropriate for the frequency range being analyzed. Note any changes made to DAS parameters.
• Units: Validate that data is being recorded in the correct units (e.g., mm/s, in/s, g).

2. Spectral Analysis Review:

• Baseline Comparison: Compare current spectra to historical baselines. Identify any shifts in amplitude or frequency.
• Frequency Identification: Accurately identify the source of dominant frequencies using known machine component speeds and harmonic relationships. Document any discrepancies.
• Amplitude Assessment: Evaluate amplitude levels relative to known limits and industry best practices. Note any exceeding values and potential causes.
• Harmonic Content: Analyze harmonic content to assess balance, alignment, and looseness issues.
• Rub/Impact Detection: Identify characteristic rub or impact frequencies and amplitudes.

3. Time Waveform Analysis:

• Waveform Shape: Examine time waveforms for distortion, spikes, or other abnormalities. Correlate waveform characteristics with spectral findings.
• Envelope Analysis (if applicable): Perform envelope analysis for gear and bearing fault detection. Evaluate envelope frequencies and amplitude patterns.

4. Phase Analysis (for multi-point monitoring):

• Phase Relationships: Verify phase relationships between sensors are consistent with expected behavior. Note any phase shifts indicating misalignment or structural issues.

5. Documentation & Follow-Up:

• Findings: Clearly document all findings, including spectral plots, time waveforms, and phase diagrams.
• Recommendations: Provide clear and actionable recommendations for maintenance or further investigation.
• Trend Data: Add data points to trend charts for long-term monitoring and performance evaluation.

Oil Analysis Checklist

Oil analysis is a cornerstone of any robust condition monitoring program. This checklist ensures comprehensive data collection and interpretation, providing vital insights into lubricant health and potential equipment issues.

I. Sample Acquisition & Preparation

• Sample Point Identification: Verify sample point location and labeling are accurate per equipment documentation.
• Sampling Procedure: Follow documented oil sampling procedure to minimize contamination.
• Sample Volume: Collect sufficient sample volume for all requested tests (typically 50-100ml, confirm with lab).
• Sample Labeling: Clearly label sample with date, equipment ID, location, and operator initials.
• Storage & Transport: Securely store and transport sample to the laboratory following proper handling procedures. Maintain sample integrity (temperature control, prevent leaks).

II. Laboratory Testing & Analysis

• Test Selection: Confirm laboratory performs all required tests:
  • Viscosity
  • Total Base Number (TBN)
  • Total Acid Number (TAN)
  • Flash Point
  • Water Content
  • Particle Count (ISO Code) - with Size Breakdown (e.g., µm)
  • Ferrous Density (ppm) - categorized by particle size
  • Wear Debris Identification (by microscopy or ferrography)
  • Lubricant Chemistry (e.g., additive depletion)
• Data Review: Review laboratory report for completeness and accuracy.
• Baseline Comparison: Compare results to established baseline values and historical data.
• Threshold Evaluation: Assess results against pre-defined alarm thresholds.

III. Interpretation & Action

• Anomaly Identification: Identify any abnormal trends or values.
• Root Cause Analysis: Investigate potential root causes of lubricant degradation or contamination. (e.g., excessive wear, coolant ingress, filtration issues)
• Corrective Action: Define and implement appropriate corrective actions (e.g., lubricant change, filtration upgrade, leak repair).
• Documentation: Record findings, corrective actions, and follow-up actions in maintenance logs.
• Re-sampling Schedule: Adjust re-sampling frequency based on findings and equipment operating conditions.

Alarm & Maintenance History Verification

This section dives into confirming the responsiveness of your system and understanding the context behind EHI fluctuations. It's more than just numbers; it's about validating that your alarm system is effective and that past maintenance actions have been properly documented and understood.

1. Alarm System Validation:

• Threshold Review: Regularly assess the sensitivity of your alarm thresholds. Are they appropriate for the equipment's operating conditions and potential failure modes? Consider adjusting thresholds based on historical data and expert judgment. Avoid overly sensitive thresholds that trigger false alarms, which can lead to alert fatigue and ignored genuine issues.
• Response Time Analysis: Document the time taken to respond to alarms. Are procedures followed promptly and efficiently? Identify and address bottlenecks in the alarm response process.
• Root Cause Analysis of Alarms: When an alarm triggers, perform a thorough root cause analysis to determine the underlying issue. Don't just address the symptom; fix the cause to prevent recurrence.

2. Maintenance History Correlation:

• Review Past Work Orders: Correlate EHI trends with past maintenance activities. For example, did a sudden drop in EHI score coincide with a specific repair? If so, was the repair successful in restoring the asset's health?
• Document Maintenance Effectiveness: Create a system for documenting the effectiveness of maintenance interventions. Did the repair solve the problem? Were there any unexpected consequences? This feedback loop helps optimize future maintenance strategies.
• Identify Recurring Issues: Look for patterns in maintenance history. Recurring problems indicate systemic issues that need to be addressed through design changes, improved operating procedures, or enhanced training.
• Maintenance Task Effectiveness: For specific maintenance tasks (e.g., lubrication, filter replacement), assess their impact on the EHI score. Are these tasks being performed effectively? Should the frequency or method be adjusted?

Action Item Tracking & Future Planning

A thorough EHI review isn't just about identifying problems; it's about ensuring those problems get resolved and that you're proactively planning for future asset health. That's where structured action item tracking and forward-looking planning become essential.

Our template includes a dedicated section for meticulously documenting all identified action items. For each issue flagged during the EHI review, record:

• Issue Description: A concise explanation of the problem.
• Responsible Party: The individual or team accountable for addressing the issue.
• Priority Level: (e.g., High, Medium, Low) based on potential impact and risk.
• Target Completion Date: A realistic deadline for resolution.
• Status: (e.g., Open, In Progress, Completed, On Hold) to track progress.
• Notes: A space for documenting steps taken, challenges encountered, and any relevant observations.

Beyond immediate actions, forward planning is key. Use the review findings to:

• Refine Condition Monitoring Strategies: Are you collecting the right data? Do alarm thresholds need adjustment?
• Update Preventative Maintenance Schedules: Incorporate new insights into your PM routines.
• Identify Opportunities for Improvement: Can process modifications or equipment upgrades enhance asset health?
• Budget for Future Investments: Use trend data to justify investments in new technologies or equipment.

By consistently tracking action items and incorporating future planning into your EHI review process, you transform a reactive exercise into a proactive driver of asset reliability and operational excellence.

Resources & Links

• Predictive Maintenance Overview: IBM - Predictive Maintenance - Provides a foundational understanding of predictive maintenance.
• EHI (Electrical Health Index) Explanation: SDT Diagnostics - What is EHI? - Details the meaning and calculation of the EHI.
• EHI vs. Other Condition Monitoring Techniques: Fluke - EHI vs. Other Condition Monitoring Techniques - Discusses how EHI fits into a broader condition monitoring strategy.
• Benefits of EHI Monitoring: ThermoPulse - Electrical Health Index (EHI) for Predictive Maintenance - Highlights the advantages of using EHI for asset health assessment.
• Equipment Specific EHI Considerations (Motors): Schneider Electric - Motor Electrical Health Index (EHI) - Focuses on how EHI is applied to motors.
• Example EHI Analysis Software: Emerson - Reliability Sciences - Showcases an example of software used for EHI analysis (many similar products exist).
• Standards and Best Practices (General Condition Monitoring): Reliability Alliance - Provides resources on general reliability and maintenance practices.
• Vibration Analysis Fundamentals: Vibronix - What is Vibration Analysis? - While not solely focused on EHI, understanding vibration is often paired.
• Infrared Thermography in Predictive Maintenance: Fluke - Infrared Thermography - Discusses another useful complementary technique.
• Case Study Examples of EHI Implementation: Rockwell Automation - Predictive Maintenance Success Stories - Provides real-world examples of predictive maintenance solutions, which might incorporate EHI.