To setup a threshold line on a chart:
In the Performance view, right-click a chart, then select Properties to open the Properties page.
In the left pane, click Thresholds to display the Thresholds property page:
Click Add New Threshold.
Specify a value in the Threshold Value field.
The line is drawn at this value on the Y‑axis.
Click the colored rectangle, then select a color from the palette.
Click Apply.
A horizontal line in the selected color displays across the chart along the specified threshold value on the Y‑axis.
To select a threshold:
In the chart’s Thresholds property page, click the Threshold drop-down list, then select a threshold.
To expand the width of the threshold band:
In the chart’s Thresholds property page, select the Use Threshold Band check box.
Specify a second value in the To number box to draw the threshold band between the values specified in the To and Threshold Value number boxes.
To delete a threshold:
In the chart’s Thresholds property page, select the desired threshold in the Threshold drop-down list, then click Delete.
The threshold setting disappears from the Threshold drop-down list.