eSTEM is designed to separate model files for different users according to a unique user ID, but exactly how users are identified and authenticated onto a server varies from environment to environment. However, all of the standard IIS mechanisms set the ASP.NET variable User.Identity.Name to a suitable value which can be used to isolate user activity. Failing this, the web service will just use a temporary session ID, but at the cost of losing persistence from one session to the next.
As explained in 8.4.4 Controlling activity logging and debug output, the web service is easily configured to create an activity log in a series of daily text files. The web service also anticipates that you might prefer to log this activity to a database, either in addition to or instead of the text files, via settings in the WebServiceMasterConfig.txt file. However it is beyond the scope of this user guide to explain in general how to configure the additional data source required by the web site in order to connect with your chosen database. Please contact Implied Logic Support if you need help with this.
The web service does not attempt to email any alerts under any error conditions, but it could in principle be made to do so. Please contact Implied Logic Support if you would like to explore adding functionality of this sort.