System concepts underlie the filed of information systems. What is a system? A system can be very simply defined as "a group of interrelated or interacting elements forming a unified whole" (James A. O Brien). Such a system (sometimes called a dynamic system) has five basic functional components that interact to form a system:
- Input involves capturing and assembling elements that enter the system so they can be processed (e.g. raw materials, energy).
- Processing involves transformation processes that convert input into output (e.g., a manufacturing processes).
- Output involves transferring elements that have been produced by the transformation process to their ultimate destination (finished products, human services).
- Feedback is data or information concerning the performance of a system.
- Control is a major system function that monitors and evaluates feedback to determine whether the system is moving toward the achievement of its goals.
A system exists and functions in an environment consisting of other systems. Also, a system is separated from its environment and other systems by its system boundary. Figure 81 shows the relationships of feedback and control to the other components of a system.
Organizations such as business firms or government agencies are subsystems of society, which is their environment (see Figure 82). Organizations are open systems since they must interface and interact with other systems to survive in their environment. Finally, organizations are adaptive systems since they possess the ability to modify themselves to meet the demands of a changing environment.