IS Design Information system that is adequatly designed and implemented is a keystone for efficient, reliable and controllable work/business environment. A good design enables prompt and efficient development of the IS and comprehensive usage of the installed devices. Based on the requirements set by the users and on the detailed analysis, the design team will develop a solution which is customized to the client needs and possibilities using the most advanced technologies and standards. Three of the most important attributes in designing IS are: Avialability of the IS, Flexibility of the IS and Simplicity of the IS. Quality of the IS design is evaluated based on it’s capability to provide continuous functionality of the supported network services. Availability is jeopardized by planned and unplanned events. The planned events are regularly scheduled maintenance activities and the unplanned are malfunctions. In order to achieve high level accessibility it is neccesary to eliminate these unplanned events or to bring them to a minimum. Information systems must support the speedy growth and development of the new services without having them influence the established infrastructure and its’ operativity. Flexible IS are capable of adapting to the ever changing business environment and of accustomization to the contemporary demands. Other key component in achieving the flexibility is the scalability of the IS. Scalability is a concept which includes proactive planning for the future requirements. scalable IS possesses the ability to support the rapid growth of the device performances, number of the devices and provided services. Major advantages of a simple IS design are minimized number of malfunctions caused by human error as well as the reducted costs of implementation, simpler monitoring system, simpler managing and low maintenance cost.