Making conclusions about your metrics impact during set review periods reduces the chance of errors and allows you to account for seasonality in your data. Split always shows your current metrics impact and if you are between review periods. The images below show the different states for active, inactive, and completed.
As a best practice, avoid making conclusive product decisions in between review periods or at minimum ensure that you have run for at least one review period.
The review period can be inactive for two reasons:
(1) Your split has not been running (or did not run) for the minimum review period configured for your organization
(2) Your split is currently running and is between review periods
The review period becomes active when the split is currently running, has met the minimum review period, and is on cycle. A 14-day review period is ready for review on day 14, 28, 42, and so forth.
The review period is completed when the version is changed and the split has run for the minimum review period for your organization.
If you believe that the default review period for your organization is too long or too short, you can reach out to your administrator to adjust your statistical settings.