There are two different types of audit trail entries:
Entries for changes caused by the interaction of a user. For example, schedule an analysis.
For this type of change, the name of the specific user is shown in the audit trail entry.
Entries for changes that occurred without a user interaction. For example, the status change of an analysis from Scheduled to In Progress.
In this case, the user name depends on how you have set up your system. By default, the installation user is shown. However, if you created a service user as described in the Sample Scheduler for OpenLab Installation & Configuration Guide for systems in a regulated environment, this service user is shown.