Statistical Interval Analysis Engine

By considering the current Out-of-Tolerance (OOT) rate and a desired reliability, Qualer can help you find the balance between:

  • Achieving desired reliability by shortening service intervals and reducing OOT events.
  • Preventing over-servicing and reducing costs by safely and scientifically extending service intervals, all while keeping the number of OOT events below the desired threshold.

Key Benefits for Asset Owners:

  • Improved Performance: adjust maintenance intervals to boost asset reliability.
  • Cost Savings: extend intervals where possible to reduce calibration costs while keeping the desired in-tolerance to the out-of-tolerance ratio.
  • Informed Decisions: confidently make changes to service intervals. Gauge the adequacy of manufacturers or service providers.


Advantages for Service Providers:

  • Customized Service: Determine which clients could benefit from shorter maintenance intervals and consider offering bespoke services to enhance reliability.
  • Procedure Validation: Identify services with higher failure rates, prompting a review and verification of existing procedures.
  • Optimized Standards: Adjust maintenance intervals for reference standards to maintain performance without incurring unnecessary costs.

Note: Statistical analysis is available for your asset maintenance plans and managed asset maintenance plans.

Interval Analysis Settings

Qualer analyzes the reliability of assets assigned to a maintenance plan using the A3 method. It compares how many assets are in/out of tolerance under a service interval and advises on increasing/decreasing the interval to reach the desired reliability.

The following configuration parameters influence the statistical advice:

  • Reliability Target
  • Change Confidence
  • Min Allowed Interval
  • Max Allowed Interval

Reliability Target: The ‘Reliability Target’ is a critical metric representing your equipment's desired operational reliability percentage. It acts as a benchmark for assessing the effectiveness of your maintenance strategy.

For essential equipment, where being out of tolerance significantly impacts operations, we recommend a robust reliability target near 98-100%. This ensures continuous operational efficiency and minimizes the risk of disruptive failures.

When equipment can tolerate occasional OOT without severe repercussions, a lower reliability target may be appropriate, balancing operational demands with maintenance costs.

Interval Change Confidence: Interval Change Confidence quantifies the level of statistical confidence in the maintenance interval change recommendation. It's a measure of how certain you want to be that the suggested intervals will meet the reliability target. It determines how much statistical data is required before the recommendation is made. A higher change confidence setting will require more data to have a recommendation made.

Minimum and Maximum Allowed Intervals

The ‘Min Allowed Interval’ and ‘Max Allowed Interval’ are expressed in months. These parameters ensure that maintenance is conducted at intervals that are neither too frequent nor too sparse, maintaining the balance between asset care and operational efficiency.

The default configuration parameters can be set in the Administration tab. After selecting Administration, go to Configuration on the left-hand side. Once in the Configuration module, select Interval Analysis.

A screenshot of a computer

Description automatically generated

These parameters can be modified later in the analysis screens to fine-tune the recommendations.

Statistical interval analysis for your assets and maintenance plans

Within the Maintenance Task, a dedicated tab now allows you to evaluate and refine calibration schedules:

  • Adjust initial settings by selecting 'Change'.
  • The analysis table: observed service intervals, tolerance metrics, and reliability data.
  • The recommended interval adjustment is highlighted above the table for easy reference.
  • Implement the suggested interval by clicking 'Apply'.
  • Activate 'Notify about new recommendations' to receive email updates when new data influences advice, ensuring your plan remains dynamic and data-driven. Please note that this feature requires the employee to subscribe to the "Maintenance Plans - Interval Recommendation Changed" notification event to be notified by email.

The Maintenance Plan manager has new alerts for the interval advice:

  • Reduce Interval
  • Increase Interval

Qualer will display the specific maintenance plans that may be modified based on a user's defined reliability and confidence targets.

Service Interval Change History

Now that maintenance intervals may be changed in reaction to the new interval analysis feature, a history of these changes may also be observed:

If multiple changes to the service interval are happening within the same day, a confirmation message is displayed, and the most recent interval is updated instead of creating a new line in the change history.

A screenshot of a confirmation

Description automatically generated









Statistical Interval Analysis for Client Assets and Maintenance Plans

The default interval analysis for a Service Provider’s client's assets and maintenance plans may be accessed from the Manage Clients screen:

The “Interval Analysis” configuration parameters are configurable here. Clicking the Calculate button will apply these parameters to all managed clients/assets/plans and provide recommendations (if any) in the table below.

Once available, results can be further filtered by “Reduce Interval” or “Increase Interval” only.

Client Maintenance plans will also have the same ability to analyze intervals. See the “Statistical interval analysis for your assets and maintenance plans” section above.

It is now possible to select clients who have recommended interval change advice and export this information to Excel or send notifications to these customers about the recommended interval change.