However, many companies have more than one roles being performed by a single person. This is mainly due to the lack of resources, limited operations and economic reasons. However, despite all this, the roles of the different people involved in any typical IT department can easily be defined separately.
The IT director being the head of the department represents the IT in the top management team. Other three categories and/or designations are the people directly involved with workings and infrastructure of the IT of the company.
The database administrator is simply the person managing the central database server of the organization. However there are significant confusions regarding the roles of the system and network administrator(s).
The field of system administration is a broad term used to define the roles and responsibilities of the person who maintains and operate the IT infrastructure of the company as a whole. A system administrator, also known as the 'sysadmin' (Microsoft, 1999), can have a work schedule ranging from a few hours per week to a full time job depending on the size of the organization. A system administrator might not even know the CEO, but he actually acts as the liaison between the technical and the non-technical staff of the organization. Some of the basic duties performed by the system administrator(s) are (Limoncelli & Hogan, 2007);
Install and maintain the user...
Determine hardware and software pre-requisites, which patches and/or plug-ins to install, which services to provide, and which services to disable.
Plan and manage the machine room environment
Design machine room; specify cooling temperatures, cabling configurations, power connections and alternate support, and environmental controls (fire alarm, security, etc.)
Schedule downtime to perform upgrades/patches, and test devices and schedule downtime to manage devices.
Install and maintain the user accounts; develop acceptable use policy and login-name policy, rights and privileges of different users; determine password change policies; install/configure/manage name services; and manage licenses.
Determine disk quota allocation, manage disk space, and monitor log files.
Configure network services (Burgess, 2002):
Printing, file sharing, name service.
Determine file sharing needs and printing policies.
Manage security for shared resources.
Other duties of a system administrator may also include scripting, programming, project management for systems-related project of automation and/or system analysis and designing, supervising and/or training computer operators, and serving as a consultant for computer related problems beyond the ordinary knowledge of the technical support staff. A System Administrator is supposed to demonstrate a versatile blend of fine tuned technical skills and responsibility.
Larger organizations have clearly defined models while smaller organizations will be likely to consolidate functions in order to maintain the health and operational capabilities of the systems. In both cases a system administrator would be there either as part of the larger IT group or as the only IT manager responsible for every system