Signal, no signal, and anti-signal
Summarize
Summary of Signal, no signal, and anti-signal
The KPI Signals application in ServiceNow identifies variations in Key Performance Indicator (KPI) scores to help you monitor workflow stability. It generatessignalswhen abnormal variations occur,anti-signalswhen no abnormal variation is detected for a significant period, and showsno signalwhen no notable variation is present but the anti-signal threshold is not yet met. This enables you to understand when workflows are statistically stable or require attention for process improvement.
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Key Features
- Signals: Indicate special cause variation in KPI scores based on three key behaviors:
- Outlier: Scores beyond three standard deviations (3-sigma) from the mean.
- Short run: Four consecutive scores on the same side of the central line, with three scores outside two standard deviations.
- Long run: Seven consecutive scores on the same side of the central line (all above or below the average).
- Anti-signals: Issued after a period with no detected signals, calculated as:
Length of baseline calculation period × Anti-signal factor.
By default, for daily indicators, the baseline is 14 days and the anti-signal factor is 2, so an anti-signal appears after 28 days of stability.
Anti-signals indicate that the workflow is under control; notifications are sent but no action is required. - No signal: Shown when no abnormal variation is detected for a shorter time than the anti-signal threshold. No notifications are sent, and no action is needed.
- Limitations: Signals are detected only for KPIs with no more than one first-level breakdown element; multiple or second-level breakdowns are not supported.
- Dashboard integration: KPI Signals-enabled indicators display insight cards on dashboards, providing proactive analytics insights.
Practical Application for ServiceNow Customers
By leveraging KPI Signals, you can easily monitor your workflows for statistical stability and quickly identify when processes experience abnormal variations. This insight helps you decide when to initiate process improvements. The generation of anti-signals reassures you that key workflows are stable over extended periods, reducing unnecessary alerts. The integration with dashboards ensures that these insights are visible where you manage your KPIs.
When KPI Signals detects abnormal variation in the scores of a KPI, it generates a signal. When KPI Signals does not detect abnormal variation for a significant amount of time, it generates an "anti-signal." The anti-signal lets you know that your workflow is under control.
- The presence of signals lets you know that a workflow has changed, or at least is not statistically stable.
- The long-term absence of signals indicates that a workflow is statistically stable. With this information you can decide to launch a process improvement initiative, for example.
Signals
- Outlier
- Every score beyond a three standard deviation (3-sigma) upper or lower limit.
- Short run
- Four consecutive scores on the same side of the central line, with three of the scores close to the upper or lower limit. "Close to the limit" is defined as outside two standard deviations.
- Long run
- Seven consecutive scores on the same side of the central line. That is, seven scores in a row all greater than or all less than the average value.
In the following example, you see a "Long run" signal: seven consecutive scores above or below the central line.
Anti-signals
Length of time to calculate the baseline for the KPI * Anti-signal factorThe application takes 14 days by default to calculate the baseline for a daily indicator. The default anti-signal factor is two. Thus, the default length of time to detect an anti-signal on a daily indicator is 28 days. For more information about setting the time to calculate a baseline, see Configure signal detection. For more information about setting the anti-signal factor, see Configure signal notifications.
In this example, the default configuration values apply to a daily indicator. The application has not detected a signal for 28 days, so it shows a 28-day anti-signal.
Although responsible users are notified when an anti-signal is generated, no action is required.
No signal
Usually no signal is detected for a shorter amount of time than it takes to detect an anti-signal. In this case, the application shows a simple "No signal" message. No notifications are sent and no action is necessary.
In the following example, no signal is detected for five days after the baseline was most recently reset. The baseline has been reset three times in the period being shown.