This paper presents the shaping of an information system on the example of system for ordering specialized examinations in hospitals. In the beginning the basic information about information systems are described, such as the main components of information systems. In the system made for the purpose of this paper the main business processes are shown and explained. As well as showing the built entity-relationship (ER) model and the relation model (RM) with explanations of their design processes. At the end of the paper there is an example of algorithms which gather needed information from the system and show the functionality of the information system.