6.2.2 Alarm evaluation

This subsection gives an explanation about alarm evaluation. The following legend applies to the contents of this subsection in general.

Legend:

--: Not issued.

Always: Whether Always notify is selected

All: Whether Evaluate all data is selected

Y: Used (selected)

N: Not used (not selected)

Organization of this subsection

(1) Differences among alarm evaluations depending on combinations of alarm conditions
(2) Differences among alarm evaluations depending on whether Damping is enabled
(3) Evaluating alarms with a monitoring time range and damping conditions specified (when "State changes for each record instance" is not selected)
(4) Evaluating alarms with a monitoring time range and damping conditions specified (when "State changes for each record instance" is selected)

(1) Differences among alarm evaluations depending on combinations of alarm conditions

The way an alarm is evaluated depends on the alarm conditions and the type of record to be evaluated. The following table describes the differences among alarm evaluations for various combinations of alarm conditions.

Table 6‒1: Differences among alarm evaluations for various alarm conditions (when "Monitor whether the value exists" is not selected)
Record type	Alarm notification	Notification target	Condition	Alarm evaluation (report)
Single-instance record	Notify when the state changed is selected	State changes for the alarm is selected	Evaluate all data is not selected	If an Abnormal condition is met, and the previously reported alarm was other than Abnormal (red), an Abnormal (red) alarm is reported. If an Abnormal condition is not met but a Warning condition is met, and the previously reported alarm was other than Warning (yellow), a Warning (yellow) alarm is reported. If neither of the above cases is met, and the previously reported alarm was Abnormal (red) or Warning (yellow), a Normal (green) alarm is reported.
		State changes for the alarm is selected	Evaluate all data is selected
		State changes for each record instance is selected	--
	Always notify is selected	--	Evaluate all data is not selected	If either an Abnormal or Warning condition is met, an Abnormal or Warning alarm is reported, regardless of any previously reported alarm.
	Always notify is selected	--	Evaluate all data is selected
Multi-instance record	Notify when the state changed is selected	State changes for the alarm is selected	Evaluate all data is not selected	If one Abnormal condition instance is found, and the previously reported alarm was other than Abnormal (red), an Abnormal (red) alarm is reported for that instance. If no instance is found that meets an Abnormal condition, one instance is found that meets a Warning condition, and the previously reported alarm was other than Warning (yellow), a Warning (yellow) alarm is reported for that instance. If none of the collected instances match the cases above, and the previously reported alarm was Abnormal (red) or Warning (yellow), a Normal (green) alarm is reported. Note: As soon as any instance is found that meets a condition, alarm evaluation ends. Therefore, not all of the collected instances are always evaluated.
		State changes for the alarm is selected	Evaluate all data is selected	If, after all of the collected instances are evaluated, one or more instances are found that meet an Abnormal condition, and the previously reported alarm was other than Abnormal (red), an Abnormal (red) alarm is reported for each of those instances. If, after all of the collected instances are evaluated, no instances are found that meet an Abnormal condition, one or more instances are found that meet a Warning condition, and the previously reported alarm was other than Warning (yellow), a Warning (yellow) alarm is reported for each of those instances. If none of the collected instances match the cases above, and the previously reported alarm was Abnormal (red) or Warning (yellow), a Normal (green) alarm is reported. Note: Because all of the instances are evaluated, more than one alarm can be reported in one interval.
		State changes for each record instance is selected	--	If, after all of the collected instances are evaluated, one or more instances are found that meet an Abnormal condition, and the alarm of the applicable instances is other than Abnormal (red), an Abnormal (red) alarm is reported for each of those instances. If, after all of the collected instances are evaluated, no instance is found that meets an Abnormal condition, one or more instances are found that meet a Warning condition, and the alarm of the applicable instances is other than Warning (yellow), a Warning (yellow) alarm is reported for each of the applicable instances. If none of the collected instances match the cases above, and the previously reported alarm of the applicable instances was Abnormal (red) or Warning (yellow), a Normal (green) alarm is reported. Note: Because all of the instances are evaluated, more than one alarm can be reported in one interval.
	Always notify is selected	--	Evaluate all data is not selected	As soon as one instance is found that meets an Abnormal condition, an Abnormal alarm is reported based on that instance, regardless of any previously reported alarm. As soon as one instance is found that meets a Warning condition but no instance has yet been found that meets an Abnormal condition, a Warning alarm is reported based on that instance, regardless of any previously reported alarm. Note: As soon as any instance is found that meets a condition, alarm evaluation ends. Therefore, not all of the collected instances are always evaluated.
	Always notify is selected	--	Evaluate all data is selected	For each instance that meets either an Abnormal or Warning condition, an Abnormal (or Warning) alarm is reported. Note: Because all of the instances are evaluated, more than one alarm might be reported in one interval.

Table 6‒2: Differences among alarm evaluations for various alarm conditions (when Monitor whether the value exists is selected)
Record type	Alarm notification	Notification target	Condition	Alarm evaluation (report)
Multi-instance record	Notify when the state changed is selected	State changes for the alarm is selected	Evaluate all data is not selected	All of the collected instances are checked for the values specified in the New Alarm > Alarm Conditions window or the Edit > Alarm Conditions window, and if no such values are found (none of the conditions are met), an Abnormal (red) alarm is reported. Note: An alarm notifying of no operation is reported only once. If no instance is collected, the alarm is not evaluated.
		State changes for the alarm is selected	Evaluate all data is selected
		State changes for each record instance is selected	--	--^#
	Always notify is selected	--	Evaluate all data is not selected	All of the collected instances are checked for the values specified in the New Alarm > Alarm Conditions window or the Edit > Alarm Conditions window, and if no such values are found (none of the conditions are met), an Abnormal (red) alarm is reported. Note: An alarm is reported every time. If no instance is collected, the alarm is not evaluated.
	Always notify is selected	--	Evaluate all data is selected

#: When Monitor whether the value exists is selected, State changes for each record instance cannot be selected.

The alarm evaluation method is explained for various alarm conditions below.

When you select Monitor whether the value exists:: All fields in records of PD and PI record types that are specified in alarm conditions are evaluated to check for the specified value. If the value is not found, the alarm is reported once per interval.
When you set alarm conditions:: When you set alarm conditions, multiple records are collected in one interval for the record of PD and PI record types to be evaluated in this alarm. If you do not select Evaluate all data, as soon as the first instance is found that meets the conditional expression, an alarm is reported and evaluation ends. Therefore, to evaluate all the performance data in an alarm, select Evaluate all data or State changes for each record instance.

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(2) Differences among alarm evaluations depending on whether Damping is enabled

In addition to the differences among alarm evaluations for various alarm conditions, if you set Damping, other differences are added to the alarm evaluation. The following table describes the differences among alarm evaluations for various alarm conditions with damping.

Table 6‒3: Differences among alarm evaluations with damping
Damping	Always	All	Alarm evaluation (notification)
Y	N	N	The alarm is reported only when the status of the alarm changes from the previously reported status. Based on the instance that indicates the highest severity at the time of reporting, the status of the alarm is reported. Note: Because the status of the alarm is determined by evaluating the damping condition, the status of the alarm might differ from the threshold of the reported instance.
Y	N	Y	The alarm is reported only when the status of the alarm changes from the previously reported status. If the status is Warning or Abnormal, the status of the alarm is reported based on all of the instances that meet the status condition at the time of reporting the alarm. Note: Because the status of the alarm is determined by evaluating the damping condition, the status of the alarm might differ from the threshold of the reported instance.
Y	Y	N	The instance that indicates the highest severity at the time of reporting the alarm is reported.
Y	Y	Y	All data that meets the warning or abnormal condition at the time of reporting the alarm is reported.

The following table describes the differences when alarms are reported depending on the value set for Damping.

Damping	When the alarm is reported
`n/m`	Always notify is not selected: The alarm is reported when the threshold is exceeded `n` times during `m` evaluations of the alarm. Subsequently, the alarm is reported only if the alarm occurs the specified number of times and the status of the alarm has changed since the previous time it was reported. Always notify is selected: The alarm is reported when the threshold is exceeded `n` times during `m` evaluations of the alarm. Subsequently, the alarm is reported every time the threshold is exceeded `n` times during `m` evaluations of the alarm.
`n/n`^#	Always notify is not selected: The alarm is reported when the threshold is exceeded `n` times during `n` evaluations of the alarm. Subsequently, the alarm is reported only if the alarm occurs the specified number of times and the status of the alarm has changed since the previous time it was reported. Always notify is selected: The alarm is reported when the threshold is exceeded `n` times during `n` evaluations of the alarm. Subsequently, the alarm is reported every time the threshold is exceeded `n` times during `n` evaluations of the alarm.

Damping

When the alarm is reported

n/m

Always notify is not selected:: The alarm is reported when the threshold is exceeded n times during m evaluations of the alarm. Subsequently, the alarm is reported only if the alarm occurs the specified number of times and the status of the alarm has changed since the previous time it was reported.
Always notify is selected:: The alarm is reported when the threshold is exceeded n times during m evaluations of the alarm. Subsequently, the alarm is reported every time the threshold is exceeded n times during m evaluations of the alarm.

n/n^#

Always notify is not selected:: The alarm is reported when the threshold is exceeded n times during n evaluations of the alarm. Subsequently, the alarm is reported only if the alarm occurs the specified number of times and the status of the alarm has changed since the previous time it was reported.
Always notify is selected:: The alarm is reported when the threshold is exceeded n times during n evaluations of the alarm. Subsequently, the alarm is reported every time the threshold is exceeded n times during n evaluations of the alarm.

#:: If Always notify is selected, the alarm is issued the first time the threshold is reached after the start of data collection, regardless of the occurrence frequency specified. Afterwards, the alarm is issued only when the alarm occurs for the specified number of times.

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(3) Evaluating alarms with a monitoring time range and damping conditions specified (when "State changes for each record instance" is not selected)

If you specify a monitoring time range, a normal alarm is issued at the specified end time. However, in calculating alarm damping, the system includes previous monitoring time ranges. An example of evaluating an alarm with a monitoring time range specified is given below.

Alarm conditions

Monitoring time range: 9:00 to 21:00
Damping: Threshold exceeded twice in three evaluations
Always notify: Not selected
Evaluate all data: Not selected

The alarm enters abnormal or warning status when the threshold is exceeded twice inside the monitoring time range for that day. When the monitoring time range is over, the alarm reverts to normal status. The following day, the status of the monitoring agent at the end of the previous day's monitoring time range (in this case abnormal or warning) is inherited at the start of the monitoring time range on the following day. Therefore, when the threshold is first exceeded in the monitoring time range of the following day, the condition of exceeding the threshold twice in three evaluations is met, and an abnormal or warning alarm is issued.

In this scenario, alarms are issued as follows:

Day	Time		Monitoring agent status	Issued alarm
First	20:58	Inside monitoring time range	Normal	--
	20:59		Abnormal	--
	21:00		Abnormal	Abnormal alarm^#1
	21:01	Outside monitoring time range	Not evaluated	Normal alarm^#2
	21:02	Outside monitoring time range	Not evaluated	--
	:
Second	8:59	Outside monitoring time range	Not evaluated	--
Second	9:00	Inside monitoring time range	Abnormal	Abnormal alarm^#3

#1: An abnormal alarm is issued because the damping condition of Threshold exceeded twice in three evaluations was met.
#2: A normal alarm (Alarm expired) is issued because the monitoring end time was reached.
#3: Because the status of the monitoring agent for the previous day is inherited, the damping condition of Threshold exceeded twice in three evaluations is met and an abnormal alarm is issued.

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(4) Evaluating alarms with a monitoring time range and damping conditions specified (when "State changes for each record instance" is selected)

If you specify a monitoring time range, a normal alarm is issued at the specified end time.

When State changes for each record instance is selected, the resultant behavior varies depending on the status of the alarm when the time falls outside the monitoring time range. If the alarm is in normal status when the time falls outside the monitoring time range, neither the occurrence frequency is cleared nor the alarm event (Alarm Expired) is reported. If, on the other hand, the alarm is in abnormal or warning status when the time falls outside the monitoring time range, the occurrence frequency is cleared and the alarm event (Alarm Expired) is reported once. When the time is in the monitoring time range, a new evaluation starts as is the case with alarm binding.

An example of evaluating an alarm with a monitoring time range specified is given below.

Alarm conditions

Monitoring time range: 9:00 to 21:00
Damping: Threshold exceeded twice in three evaluations
State changes for each record instance: Selected
Evaluate all data: Not selected

The alarm enters abnormal or warning status when the threshold is exceeded twice inside the monitoring time range for that day. When the monitoring time range is over, the alarm reverts to normal status. The following day, the status of the monitoring agent at the end of the previous day's monitoring time range (in this case abnormal or warning) is not inherited at the start of the monitoring time range. Therefore, when the threshold is exceeded twice in the monitoring time range of the following day, the condition of exceeding the threshold twice in three evaluations is met.

In this scenario, alarms are issued as follows:

Day	Time		Monitoring agent status	Issued alarm
First	20:58	Inside monitoring time range	Normal	--
	20:59		Abnormal	--
	21:00		Abnormal	Abnormal alarm^#1
	21:01	Outside monitoring time range	Not evaluated	Normal alarm^#2
	21:02	Outside monitoring time range	Not evaluated	--
	:
Second	8:59	Outside monitoring time range	Not evaluated	--
	9:00	Inside monitoring time range	Abnormal	--^#3
	9:01	Inside monitoring time range	Abnormal	Abnormal alarm^#1

#1: An abnormal alarm is issued because the damping condition of Threshold exceeded twice in three evaluations was met.
#2: The damping value is cleared and a normal alarm (Alarm expired) is issued because the monitoring end time was reached.
#3: Because the status of the monitoring agent for the previous day is not inherited, the damping condition of Threshold exceeded twice in three evaluations is not met.

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