Any actions taken in the Tanium environment will always have an associated expiration time. "Scheduled" or "policy" actions are reissued periodically, but each instance of these actions has an associated expiration value.
In Tanium an expiration time is the period of time that Tanium allows for each Client to download the necessary Package files and execute the associated command. Even if the Action is still executing, the Tanium Client will terminate an action that has reached its expiration time value to prevent hanging processes or unexpected behavior. Because of this behavior, you must configure the expiration value for an action to have an adequate amount of time to execute.
Seeing which Actions are Active versus Expired
In the Actions -> Action History tab, you can see which Actions are currently active or expired by looking at the Status column.
Modifying the Command Timeout Value for a Package
Actions remain active for 10 minutes plus the "Command Timeout" value, which defaults to 1 minute. This timeout value can be changed in the Package definition.