The _system_user is INTERNAL:

discussed in MicroFocus KB article KM02943875:

The _system_user_ is an internal user used by ALM with a type of "ALM Server Internal" in order to perform internal operations. It was introduced in ALM 11.
Any operations on ALM entities are monitored by the permissions granted to the user performing them and thus an internal user is needed. For example, QPM Calculation engine needs to access to different projects and entities.

Here are some characteristics for this user:
- It does not have a password and it is internal thus preventing login using this user.
- It does not consume a license. This is a user created for internal server jobs proposes.
- This user is created upon installation/upgrade process.
- It enables automatically on project creation, as part of the TDAmin group. This indicates that the user's permissions are equal to regular admin user.
- The user is hidden from the Site Administrator's users list and it does not appear as one of the users enabled on the projects. This is done to prevent deleting the user or changing its properties.
- The records on the user are stored inside the qcsiteadmin_db. If the user list is managed using LDAP, the user is not defined in it. Its scope is only inside ALM since it is not representing a normal user.