Viz metrics are generated based on Flow Item & Flow State mapping set on the Artifact Modeling tab in Viz. As part of modeling, users may additionally set conditions based on specific fields on each artifact.
Sometimes, metadata will change on an artifact within an external tool, leading to changes in how metrics are calculated. For example, if Artifact #123 is changed from a story to a defect in Jira, Viz may consider it a feature one day, and a defect the next.
For Flow Velocity®, Flow Distribution®, Flow Time, and Flow Efficiency® (i.e., metrics involving 'Done' artifacts), what matters is the metadata on the artifact at the time it closed. For example, if a label is applied to an artifact, or the artifact type is changed after it has already moved to 'Done,' your metrics will remain unchanged (i.e., Viz will not 'rewrite history').
In contrast, Flow Load®metrics (which refer to artifacts that are currently in progress) will reflect the metadata of the artifact on each individual day.
To better understand how changes to metadata within an external tool will impact Viz metrics, let’s look at an example:
July 1: A defect artifact is 'In Progress'
July 5: The defect is changed to a story in the external tool
July 10: The artifact (now a story) is moved to 'Done'
July 11: The artifact is now changed from a story back to a defect
In this scenario, we'd see the following behavior in Viz: