Understanding Process+ KPIs

Process+ KPIs are calculated from collected interim data. Determined by the type of Process+ Action Object deployed, different calculated values are generated, or different aspects of the control loop specified in the loop configuration information is calculated. The Process+ KPIs are stored in the CSense Data Server.

The following table describes the different Process+ KPIs and how they are calculated:

KPIs for Loop Performance

KPI Names	Description	Formula
Auto (%)	Calculates the percentage of time the control loop operated in the Auto control mode for the reporting period.	Where, NumberofAutoGoodSamples is the number of samples that were in the Auto control mode and also of a good quality. For more information, refer to Good Quality. PercentageGoodQuality is the percentage good quality values over the reporting period for a specific loop. That is, the time that the data was not of bad quality. For more information, refer to Percentage Good Quality.
Auto Lower Limit %	Calculates the percentage of time the control loop operated in the Auto control mode and PV exceeded the lower limit.	Where, NumberofAutoSamplesLimitsExceeded is the number of samples in the Auto control mode that exceeded the limits. A sample is considered lower limits exceeded when Error< - (Lower SP Offset). PercentageGoodQuality is the percentage good quality values over the reporting period for a specific loop. That is, the time that the data was not of bad quality. For more information, refer to Percentage Good Quality.
Auto Upper Limit %	Calculates the percentage of time the control loop operated in the Auto control mode and PV exceeded the upper limit.	Where, NumberofAutoSamplesLimitsExceeded is the number of samples in the Auto control mode that exceeded the limits. A sample is considered upper limits exceeded when Error > - (Upper SP Offset). PercentageGoodQuality is the percentage good quality values over the reporting period for a specific loop. That is, the time that the data was not of bad quality. For more information, refer to Percentage Good Quality.
Average Absolute Error	The absolute value of the error between the PV and SP, averaged across all good quality samples for the reporting period.	Where, Error is the difference between PV and SP. For more information, refer to Error. TotalSamples is the total number of samples. For more information, refer to Total Number of Samples.
Average Absolute Error %	The average absolute value of the tag error, where the tag error is the difference between process variable and set point. Expressed as a percentage of PV Span.	Where, pvSpan = pvMax - pvMin pvMax is the maximum good quality value of pv during the reporting period. pvMin is the minimum good quality value of pv during the reporting period. AverageAbsoluteError is the absolute value of the error between the PV and SP, averaged across all good quality samples for the reporting period. For more information, refer to Average Absolute Error.
Average MV Change [%]	The average of movement in the manipulated variable (MV Rate of change). This value is displayed as a percentage due to the MV range being [0-100].	Where, MVRoc is the rate of change of MV. For more information, refer to MVRoc. TotalSamples is the total number of samples. For more information, refer to Total Number of Samples.
Average Error	The average error between the PV and the SP for all good quality samples across the reporting period.	Where, Error is the difference between PV and SP. For more information, refer to Error. TotalSamples is the total number of samples. For more information, refer to Total Number of Samples.
Average Oscillation Amplitude [%]	The average amount of movement in the manipulated variable before changing its direction.	Where, MVRoc is the rate of change of MV. For more information, refer to MVRoc. ReverseIndex is the number of times MV changes its direction.
AVG Absolute Error (Aggregate)	The average of all the Absolute Error values over the reporting period for a specific loop, where the tag error is the difference between the process variable and the set point.	Where, AverageAbsoluteError is the absolute value of the error between the PV and SP for all good quality samples across the reporting period. For more information, refer to Average Absolute Error.
AVG Auto (%)	The average of all the Percentage Auto values over the reporting period for the control loop.	Where, PercentageAuto is the percentage of time the control loop operated in the Auto control mode for the reporting period. For more information, refer to Auto Percentage.
AVG Cascade (%)	The average of all the Percentage Cascade values over the reporting period for the control loop.	Where, PercentageCascade is the percentage of time the control loop operated in Cascade control mode for the reporting period. For more information, refer to Cascade Percentage.
AVG MV Saturation (%)	The average of all the Percentage MV Saturation values over the reporting period for the control loop.	Where, PercentageMVSaturation is the percentage of time a MV is saturated. For more information, refer to MV Saturation.
AVG Limits Exceeded (%) (Auto + Cascade + Manual)	Average of the Percentage Limits Exceeded over the reporting period for the control loop.	Where, PercentageLimitsExceeded is the percentage of time the control loop operated in the Manual, Auto or Cascade control mode and exceeded the upper or the lower limit. For more information, refer to Limits Exceeded.
AVG Limits Exceeded (%) (Auto + Cascade)	Average of the performance index over the reporting period for the control loop.	Where, PerformanceIndex is the percentage of time when Auto and Cascade Limits Exceeded. For more information, refer to Performance Index.
AVG Manual (%)	The average of all the Percentage Manual values over the reporting period for the control loop.	Where, PercentageManual is the percentage of time the control loop operated in the Manual control mode for the reporting period. For more information, refer to Manual percentage.
AVG Performance Index (100 - 0)	Average of the Overall Performance over the reporting period for the control loop.	Where, OverallPerformance is the performance of the loop by combining Manual (%), MV Saturation [%], and Limits Exceeded (%) into a single percentage value. For more information, refer to Overall Performance.
AVG PV Variability	The average of all the PV Variability values over the reporting period for the control loop.	Where, PVVariability is the variability of PV. For more information, refer to PV Variability.
AVG Shutdown (%)	The average of all the Percentage Shutdown values over the reporting period for the control loop.	Where, PercentageShutdown is the percentage of time the control loop operated in the Shutdown control mode for the reporting period. For more information, refer to Shutdown Percentage.
Cascade (%)	Calculates the percentage of time the control loop operated in Cascade control mode for the reporting period.	Where, NumberofCascadeGoodSamples is the number of samples that were in the Cascade control mode and also of a good quality. For more information, refer to Good Quality. PercentageGoodQuality is the percentage good quality values over the reporting period for a specific loop. That is, the time that the data was not of bad quality. For more information, refer to Percentage Good Quality.
Cascade Lower Limit %	Calculates the percentage of time the control loop operated in Cascade control mode and PV exceeded the lower limit.	Where, NumberofCascadeSamplesLimitsExceeded is the number of samples in the Cascade control mode that exceeded the limits. A sample is considered lower limits exceeded when Error< -(Lower SP Offset). PercentageGoodQuality is the percentage good quality values over the reporting period for a specific loop. That is, the time that the data was not of bad quality. For more information, refer to Percentage Good Quality.
Cascade Upper Limit %	Calculates the percentage of time the control loop operated in Cascade control mode and PV exceeded the upper limit.	Where, NumberofCascadeSamplesLimitsExceeded is the number of samples in the Cascade control mode that exceeded the limits. A sample is considered upper limits exceeded when Error > - (Upper SP Offset). PercentageGoodQuality is the percentage good quality values over the reporting period for a specific loop. That is, the time that the data was not of bad quality. For more information, refer to Percentage Good Quality.
Duration %	Percentage of time the control mode was in the given modes.	See formulas for Shutdown (%), Cascade (%), Auto (%), and Manual (%).
Duration Not Utilized [%]	The percentage of time where the loop is not being utilized. The loop is considered to be not utilized if it is in manual mode or if the controller output is saturated. The controller output is considered saturated when the MV has a value of 0 (the lower limit for controller output saturation) or 100 (the upper limit for controller output saturation).	Where, NumberofSamplesNotUtilized is the actual number of samples that were not utilized. TotalSamples is the total number of samples. For more information, refer to Total Number of Samples.
Error Std Deviation	The standard deviation of the tag error, where the tag error is the difference between process variable and set point.	Where, Error is the difference between PV and SP. For more information, refer to Error. AvgError is the average error between the PV and the SP for all good quality samples across the reporting period.. For more information, refer to Average Error. TotalSamples is the total number of samples. For more information, refer to Total Number of Samples.
% Good quality data	Calculates the Percentage Good Quality values over the reporting period for a specific loop. That is, the time that the data was not of bad quality.	Where, NumberofGoodSamples is the total number of all the good samples. For more information, refer to Good Quality. TotalSamples is the total number of samples. For more information, refer to Total Number of Samples.
Good Quality Data (%)	The average of all Percentage Good Quality values over reporting period for specific loop.	Where, PercentageGoodQuality is the percentage good quality values over reporting period for specific loop. For more information, refer to Good Quality Data.
Integrated Error	The sum of the absolute values of the Error. That is, the sum of all differences between the process variable and the set point.	Where, Error is the difference between PV and SP. For more information, refer to Error.
Limits Exceeded (%)	Calculates the percentage of time the control loop operated in the Manual, Auto or Cascade control mode and exceeded the upper or the lower limit.	Where, PercentageManualLLExceeded is the percentage of time the control loop operated in the Manual control mode and PV exceeded the lower limit. For more information, refer to Percentage Manual Lower Limit Exceeded. PercentageManualULExceeded is the percentage of time the control loop operated in the Manual control mode and PV exceeded the upper limit. For more information, refer to Percentage Manual Upper Limit Exceeded. PercentageAutoLLExceeded is the percentage of time the control loop operated in the Auto control mode and PV exceeded the lower limit. For more information, refer to Percentage Auto Lower Limit. PercentageAutoULExceeded is the percentage of time the control loop operated in the Auto control mode and PV exceeded the upper SP offset inside the data window. For more information, refer to Percentage Auto Upper Limit. PercentageCascadeLLExceeded is the percentage of time the control loop operated in the Cascade control mode PV and exceeded the lower SP offset inside the data window. For more information, refer to Percentage Cascade Lower Limit. PercentageCascadeULExceeded is the percentage of time the control loop operated in the Cascade control mode and PV exceeded the upper SP offset inside the data window. For more information, refer to Percentage Cascade Upper Limit. PercentageManual is the percentage of time the control loop operated in the Manual control mode for the reporting period. For more information, refer to Manual percentage. PercentageCascade is the percentage of time the control loop operated in Cascade control mode for the reporting period. For more information, refer to Cascade Percentage. PercentageAuto is the percentage of time the control loop operated in the Auto control mode for the reporting period. For more information, refer to Auto Percentage.
Manipulated Variable [%]	The average of MV for the reporting period. Represented as a percentage due to the range of MV [0-100].	Where, MV is the manipulated variable. TotalSamples is the total number of samples. For more information, refer to Total Number of Samples.
Manual (%)	Calculates the percentage of time the control loop operated in the Manual control mode for the reporting period.	Where, NumberofManualGoodSamples is the number of samples that were in the Manual control mode and also of a good quality. For more information, refer to Good Quality. PercentageGoodQuality is the percentage good quality values over the reporting period for a specific loop. That is, the time that the data was not of bad quality. For more information, refer to Percentage Good Quality.
Manual Lower Limit %	Calculates the percentage of time the control loop operated in the Manual control mode and PV exceeded the lower limit.	Where, NumberofManualSamplesLimitsExceeded is the number of samples in the Manual control mode that exceeded the limits. A sample is considered lower limits exceeded when Error< -(Lower SP Offset). PercentageGoodQuality is the percentage good quality values over the reporting period for a specific loop. That is, the time that the data was not of bad quality. For more information, refer to Percentage Good Quality.
Manual Upper Limit %	Calculates the percentage of time the control loop operated in the Manual control mode and PV exceeded the upper limit.	Where, NumberofManualSamplesLimitsExceeded is the number of samples in the Manual control mode that exceeded the limits. A sample is considered upper limits exceeded when Error > - (Upper SP Offset). PercentageGoodQuality is the percentage good quality values over the reporting period for a specific loop. That is, the time that the data was not of bad quality. For more information, refer to Percentage Good Quality.
MV Oscillation Count [#]	The number of times MV oscillates.	Where, ReverseIndex is the number of times MV changes its direction.
MV Saturation [%]	The percentage of time that the MV is saturated. The controller output is considered as saturated when the MV has a value of 0% (the lower limit for controller output) or 100% (the upper limit for controller output). Only good quality data is considered.	Where, SaturationCount is the number of samples where MV is 0. TotalSamples is the total number of samples. For more information, refer to Total Number of Samples.
No. of samples	The total number of expected samples in the reporting period. Note that this is a calculated value.	Where, Duration is the duration (time in seconds) of the reporting period. SamplingPeriod is the rate at which data is sampled (in seconds).For more information, refer to sampling period.
%Time when control on	The percentage of time data was not of a bad quality and the controller is On. The controller is considered on, when the control loop operated in the Auto and the Cascade mode for good quality samples.	Where, NumberofAutoGoodSamples and NumberofCascadeGoodSamples are the total number of all the good quality samples that operated in the Auto and the Cascade control mode. For more information on good samples, refer to Good Quality. TotalSamples is the total number of samples. For more information, refer to Total Number of Samples.
Period (Seconds)	The period (in seconds) of the frequency with the highest associated amplitude on the FFT graph for the reporting period. Note that this KPI can only be calculated when there is 100% good quality data for the period for which the FFT is calculated, otherwise this KPI will return -1.	NA.
PIDF Configuration Changes	Calculates the sum of the number of times any of the PIDF values changed during the reporting period.
PV Oscillations	Name of the peak. The highest value of PV is considered as a peak. The name of the peak is displayed along with the Period at which the signal was at the peak, and the Strength of that respective peak at that specific period. Note that this KPI can only be calculated when there is 100% good quality data for the period for which the FFT is calculated, otherwise this KPI will return -1.	NA.
PV Variability	Calculates the variability of PV.	NOTE:In case if PV Average is zero, then the PV Variability will also be zero. Where, PVStandardDeviation is the standard deviation of PV. For more information, refer to PV Standard Deviation. PVAverage is the average of PVs. For more information, refer to PV Average.
PV Variance [%]	Calculates the percentage of PV Variance.	Where, PV is the value of a PV. PVAverage is the average of PVs. For more information, refer to PV Average. TotalSamples is the total number of samples. For more information, refer to Total Number of Samples.
Report Start (Actual)- D	Retrieves the value of D at the beginning of the reporting period.	NA.
Report End (Actual)- D	Retrieves the value of D at the end of the reporting period.	NA.
Report Start (Actual)- F	Retrieves the value of F at the beginning of the reporting period.	NA.
Report End (Actual)- F	Retrieves the value of F at the end of the reporting period.	NA.
Report Start (Actual)- I	Retrieves the value of I at the beginning of the reporting period.	NA.
Report End (Actual)- I	Retrieves the value of I at the end of the reporting period.	NA.
Report Start (Actual)- P	Retrieves the value of P at the beginning of the reporting period.	NA.
Report End (Actual)- P	Retrieves the value of P at the end of the reporting period.	NA.
Sampling period	The rate at which data is sampled. Sampling period is measured in seconds.	NA.
Shutdown (%)	Calculates the percentage of time the control loop operated in the Shutdown control mode for the reporting period.	Where, NumberofShutdownGoodSamples is the number of samples that were in the Shutdown control mode and also of a good quality. For more information, refer to Good Quality. PercentageGoodQuality is the percentage good quality values over the reporting period for a specific loop. That is, the time that the data was not of bad quality. For more information, refer to Percentage Good Quality.
Shutdown Lower Limit %	Calculates the percentage of time the control loop operated in the Shutdown control mode and PV exceeded the lower limit.	Where, NumberofShutdownSamplesLimitsExceeded is the number of samples in the Shutdown control mode that exceeded the limits. A sample is considered lower limits exceeded when Error< -(Lower SP Offset). PercentageGoodQuality is the percentage good quality values over the reporting period for a specific loop. That is, the time that the data was not of bad quality. For more information, refer to Percentage Good Quality.
Shutdown Upper Limit %	Calculates the percentage of time the control loop operated in the Shutdown control mode and PV exceeded the upper limit.	Where, NumberofShutdownSamplesLimitsExceeded is the number of samples in the Shutdown control mode that exceeded the limits. A sample is considered upper limits exceeded when Error > - (Upper SP Offset). PercentageGoodQuality is the percentage good quality values over the reporting period for a specific loop. That is, the time that the data was not of bad quality. For more information, refer to Percentage Good Quality.
Statistics Period (Days)	Number of days in the reporting period.	NA.
Strength (%power)	The power for the point in the FFT graph for which the amplitude is highest, expressed as a percentage of the total power in the frequency spectrum of the FFT for the reporting period. Note that this KPI can only be calculated when there is 100% good quality data for the period for which the FFT is calculated, otherwise this KPI will return -1.	Where, MaxPeak is the highest value of a peak. Where, PV is the value of a PV. NumberofGoodSamples is the total number of all the good samples. For more information, refer to Good Quality.
Total Configuration Changes	The total number of PIDF changes over the reporting period for a specific loop.	Where, PIDFChanges is the sum of number of times any of the PIDF values changed during the reporting period. For more information, refer to PIDF Changes.
Total MV Movement	The Movement Index gives an indication of the absolute sum of all the MV movements.	Where, MVRoc is the rate of change of MV. For more information, refer to MVRoc.
Total MV Movement (average loop performance)	The sum of all the Movement Index values over the reporting period for a specific loop.	Where, TotalMVMovement is the Movement Index gives an indication of the absolute sum of all the MV movements. For more information, refer to Total MV Movement.
Total Limits %	The total percentage of time the control mode was exceeding its limits.	For the Auto control mode, For the Cascade control mode, For the Manual control mode, For the Shutdown control mode, For more information, refer to the following: PercentageAutoLowerLimitExceeded PercentageAutoUpperLimitExceeded PercentageCascadeLowerLimitExceeded PercentageCascadeUpperLimitExceeded PercentageManualLowerLimitExceeded PercentageManualUpperLimitExceeded PercentageShutdownLowerLimitExceeded PercentageShutdownUpperLimitExceeded.

Additional KPIs used for Internal Calculations

KPIs	Description	Formula
MVRoc	The rate of change of MV.	NOTE:The quality for MVRoc will be the worst quality of the two samples.
Error	The difference between PV and SP.	NOTE:The quality of Error will be the worst qualty between PV and SP.
PVAverage	The average of PV.	Where, PV is the value of a PV. TotalSamples is the total number of samples. For more information, refer to Total Number of Samples.
PVStandardDeviation	The standard deviation of PV.	Where, PV is the value of a PV. PVAverage is the average of PVs. For more information, refer to PV Average. TotalSamples is the total number of samples. For more information, refer to Total Number of Samples.
OverallPerformance	Calculates the overall performance of the loop by combining Manual (%), MV Saturation [%], and Limits Exceeded (%) into a single percentage value.	Where, PercentageManual is the percentage of time the PV operated in the Manual control mode, inside the data window. For more information, refer to Manual percentage. PercentageMVSaturation is the percentage of time a MV is saturated. For more information, refer to MV Saturation. PercentageCascade is the percentage of time the PV operated in Cascade control mode, inside the data window. For more information, refer to Cascade Percentage.
PerformanceIndex	Calculates the percentage of time in the Auto or Cascade control mode and exceeding the upper or the lower limits.	Where, PercentageAutoLLExceeded is the percentage of time the PV operated in the Auto control mode and exceeded the lower SP offset inside the data window. For more information, refer to Percentage Auto Lower Limit. PercentageAutoULExceeded is the percentage of time the PV operated in the Auto control mode and exceeded the upper SP offset inside the data window. For more information, refer to Percentage Auto Upper Limit. PercentageCascadeLLExceeded is the percentage of time the PV operated in the Cascade control mode and exceeded the lower SP offset inside the data window. For more information, refer to Percentage Cascade Lower Limit. PercentageCascadeULExceeded is the percentage of time the PV operated in the Cascade control mode and exceeded the upper SP offset inside the data window. For more information, refer to Percentage Cascade Upper Limit. PercentageAuto is the percentage of time the PV operated in the Auto control mode, inside the data window. For more information, refer to Auto Percentage. PercentageCascade is the percentage of time the PV operated in Cascade control mode, inside the data window. For more information, refer to Cascade Percentage.

What is a Good Quality Sample?

A sample is considered to be of a good quality, when the quality for each of the following fields are considered good:

Control Type
Error
LL
LLFlag
MV
MVRevIndex
MVRoc
PV
SP
UL
ULFlag