Step 6.1 Monitor, measure and analyze key characteristics
Key characteristics are specific variables that determine an organization’s energy performance. These key characteristics of operations that determine energy performance are
 regularly to confirm operation at peak efficiency, detect performance degradation and verify the effect of improvement activities.
The Monitoring and Measurement of Key Characteristics Planning Worksheet helps identify the key characteristics and their monitoring and measurement requirements. An Example Monitoring and Measurement of Key Characteristics Planning Worksheet is also provided.
What’s included in key characteristics?
A description of each key characteristic and the need for measuring, monitoring and analysis appears below. If this refresher is not needed, then skip directly to:
Significant energy uses
Significant energy uses
 are an important focus of the EnMS because they have been identified by the organization as major energy users or areas with great potential for energy improvement. As major energy users, the significant energy uses will typically consume a large percentage of the organization’s energy. Consequently, small changes in operations or deviations in procedures, equipment or maintenance can affect the organization’s overall energy consumption. Regular monitoring and measurement will allow the organization to determine current performance, compare with past history and detect changes that can be addressed to restore effective operation and control energy use and consumption.
Energy performance indicators (EnPIs)
Energy performance indicators (EnPIs)
 are the measures of energy performance that have been defined by the organization. These indicators may be defined for equipment, process, department, production line, facility or other appropriate organizational component. EnPIs are vital items to monitor as they provide critical information about the performance of the entities for which they have been defined.
Energy sources and past and present energy use and consumption
Energy review outputs include the organization’s energy sources, past and present energy consumption and use, and the current energy performance of facilities, equipment, systems, and processes associated with significant energy uses. These are components of the energy review that provide data for evaluating energy performance and consumption. Energy sources and past and present energy consumption at a facility level is generally available from regular monthly utility bills. Energy consumption and use data below the facility level e.g. systems and equipment is obtained through submetering, equipment instruments and portable analyzers. Energy performance is also measured with metering and analysis equipment.
Variables associated with significant energy uses
Variables associated with significant energy uses are those things that can have an effect on the consumption of energy associated with that significant energy use. Examples include line speeds, moisture levels, equipment efficiency, firing rate, etc. Accurate determination of relevant independent variables is an important contributor to the proper modeling and associated performance analysis. Consult with equipment manufacturers, operators, maintenance personnel, and review performance data and similar processes to determine the parameters that impact energy use and consumption. Analysis of the data collected for these variables provides important information about the performance of the significant energy use.
Action plan effectiveness
Action plans are developed to meet the objectives and targets associated with identified energy opportunities. The action plans are monitored, measured and analyzed to ensure targets and objectives are being met effectively. The expected energy consumption associated with projects that are implemented to meet objectives and targets is compared to the actual results after project completion to determine if objectives and targets were met. Successful projects are analyzed for appropriate reproduction in other processes. Projects where targets are not met are analyzed to determine the reason(s) for the shortfall and appropriate follow-up is planned and implemented. The action plan can be analyzed during and/or after completion.
Action plans that are not effective
 are modified as required.
Actual versus expected energy consumption
The organization monitors the actual energy consumption of processes, equipment, systems or facilities and compares that to the expected consumption. Expected consumption is the consumption that can be associated with past experience, project initiations, production plans and/or strategic initiatives and goals. The expectations can be based on detailed analysis of these and other issues or general estimates from past trends. Variances are analyzed and evaluated to identify elements that improve performance for possible duplication or isolate problems that should be addressed. This can be a component of the action plan evaluation.
Future energy use of the significant energy uses
Future energy use and consumption is estimated for the significant energy uses as part of the energy review (See Step 2.3). The organization determines the length of time considered to be “future” and monitors the assumptions or criteria used to estimate future energy use. Appropriate data is collected and analyzed and adjustments are made as required to maximize energy performance. Items to consider in estimating future energy use include equipment purchase plans, product changes, production plans, market conditions, fuel availability, improvement projects, etc. The SEU Future Energy Estimate Worksheet provides items to consider and will help estimate future energy use and consumption. This Worksheet may have already been completed in Step 2.3.5.
Prioritized opportunities for improvement
Opportunities for improvement are another output of the energy review and can be identified by energy assessments, by data collected through monitoring and measurement activities or through various other methods (see Step 2.4). However identified, the opportunities are evaluated and prioritized based on criteria defined by the organization (see Step 2.5). The organization either pursues appropriate opportunities further with development of objectives, targets and action plans or removes them from the active list. Further monitoring or measurement may be required to collect data to verify the suitability of installation procedures, operating criteria and control and maintenance practices for the opportunity.
Define and implement an energy measurement plan

ISO 50001 requires an energy measurement plan. The energy measurement plan is developed to define, organize and document the monitoring and measurement activities. Each of the key characteristics is evaluated to determine the appropriate quality(s) that should be measured or monitored so appropriate data can be collected for analysis.
 to include in the plan will vary depending on the size and complexity of the organization and its monitoring and measuring equipment. Typically, the plan would include at a minimum:
  • specification of the systems, processes or equipment to be monitored or measured,
  • the frequency of data collection,
  • collection method(s),
  • description of the data analysis process, and
  • calibration requirements (see Step 6.2).
Once the key characteristics and monitoring and measurement requirements are identified, the Energy Measurement Plan Worksheet provides a guide to the details required to ensure adequate data collection for determining energy performance. This form is used for an overall look at the relevant key characteristics. More detailed information may be required for some equipment or systems and the Equipment Energy Measurement Plan can be used for additional detail. An Example Equipment Energy Measurement Plan is also provided.
In addition to defining its measurement needs, the organization must review them periodically. Changes to monitoring and measurement methods, equipment, procedures, personnel, and the like typically are implemented in response to changes in key characteristics (e.g. significant energy uses) or the need to meet other EnMS or energy performance requirements (e.g. new objectives, targets and action plans). The data collected by the monitoring and measurement activities is used to analyze energy performance and results of these activities are recorded.
Investigate and respond to significant deviations

The key characteristics determine energy performance and the data collected by monitoring and measurement of these attributes is used to identify significant deviations. The organization determines what will be considered a significant deviation but, in general, it is a departure from a level of energy performance that is acceptable, defined or expected. A deviation may be identified by a specific level of variation or can be evaluated by knowledgeable personnel to determine if it is significant and if action is required. Significant deviations can be an improvement as well as a decline in energy performance.
Examples of methods for specifying significant deviations can include:
  • Values outside of control limits
  • Percent variation in value
  • Trends identified
  • Specified variation in EnPIs
  • Level of variance between expected and actual performance
  • Change in equipment efficiency
  • Variation in specific variable performance
  • Failure to meet objectives and targets
  • Failure to meet a specific performance level
Significant deviations must be investigated and an appropriate response developed. The investigation addresses normal operation, as well as evaluation of energy use and consumption expected as the result of process changes or implementation of improvement opportunities. Significant deviations that result in improved energy performance can be analyzed for actions to be replicated in other energy systems. The organization determines if significant deviations will be handled through the corrective action system (see Step 6.5) or investigated through another process. Results of investigation and the response(s) need to be recorded.
Make monitoring and measurement connections for significant energy uses

The Significant Energy Uses Control Chart introduced in Step 2.3.4 and then again in Step 5.2 is intended as a concise roadmap to the organization’s management of its significant energy uses. It is designed to capture the connections between each significant energy use and the associated operational controls, training, monitoring and measurement, and calibration required by ISO 50001. Column 6 of that chart can be used to record information or references to the monitoring and measurement that is put in place to track key characteristics of the significant energy uses. An Example Significant Energy Uses Control Chart is available here.