A public accuracy test (PAT) should be completed both before and after the election to ensure tabulators are properly calibrated. Also, PATs should be performed at random times during Election Day. To limit underlying vulnerabilities as system alterations can occur through hacker interference, a duplicate PAT is recommended at both the close of, as well as random tests during Election Day to verify system accuracy.
To see the process for MI: https://www.youtube.com/watch?v=yBJT_xWUgXw