Add automated technical commentary

[ThomUK]

For example:

Variation: The most recent point is showing common-cause variation, meaning that this metric is not changing in a statistically significant way.

Assurance: This metric can be expected to mostly fail its target.

Combined comment: In light of the common-cause variation, combined with expected failure of target, something needs to change. Consider designing some improvement activity, or altering the target level (if appropriate and compatible with business priorities).