Final answer:
When setting up a new user in Salesforce, administrators must assign the correct profile to determine permissions and ensure that the user is granted login access to use the system. Other details like naming or passwords are typically handled by the user upon initial setup.
Step-by-step explanation:
When creating a new user in a production Salesforce org, a System Administrator should consider several mandatory requirements. Among them, two key aspects are to ensure that the user is assigned the correct profile and given login access permissions. While providing a strong password and specifying the user's first and last name are important, the password usually is set by the user themself upon initial login, and the names do not impact the user's access or permissions.
Assigning the user to the correct profile is crucial as the profile contains settings and permissions that control what the user can do within Salesforce. Without the correct profile, the user may either be restricted from necessary tasks or may have too much access, potentially leading to security issues.
Additionally, granting login access to the user is important as it determines whether the user can log into the Salesforce org in the first place. Without login access, creating a user would be pointless because the user would not be able to work within the system.