Information system
An information system is a unity with overall functions and comprehensive behaviors composed of interrelated, interdependent, and interacting things or processes. In economic and social activities, the concept of "system" is often used, for example, business systems and financial systems in the economic field, water conservancy systems and ecological systems in nature, etc. From a mathematical point of view, a system is a set, which is a set composed of many interacting and interdependent things (set elements) to achieve a certain goal.
1. Information systems and their characteristics
Simply put, an information system is a system that inputs data, processes it, and finally generates information. Management-oriented and production-supporting are the salient features of information systems. Computer-based information systems can be defined as: combining management theories and methods, applying information technology to solve management problems, improving production efficiency, and providing services for production or informatization processes as well as management and A system that supports decision-making. Information system is a combination of management model, information processing model and system implementation conditions.
The management model refers to the specialized knowledge in the field of the system's service objects, as well as the model for analyzing and processing problems in this field, also known as the object's processing model; the information processing model refers to the structure and method of the system processing information. The theories and analytical methods in the management model are transformed into rules for information acquisition, storage, transmission, processing and use in the information processing model; system implementation conditions refer to the applicable computer technology and communication technology, and the personnel working in the object field, and the control and integration of these resources.
The components of an information system include hardware, software, databases, networks, storage devices, sensing devices, peripherals, personnel, and procedures for processing data into information. Divided by type of use, information systems generally include e-commerce systems, transaction processing systems, management information systems, manufacturing systems, e-government systems, decision support systems, etc.
2. Information system life cycle
Information systems are specific applications in human production and life in the real world, and exist to improve the quality and efficiency of human activities. The purpose, performance, internal structure and order, external interfaces, component composition, etc. of the information system are planned by people. Its generation, construction, operation and improvement constitute a cyclic process, which follows certain laws. In addition, the construction period of information systems is long, the investment is large, the risks are high, and it is more difficult and complex than ordinary technical projects. During its use, as the living environment changes, it needs to be continuously maintained and modified. When it is no longer When it adapts, it will be eliminated and the old system will be replaced by the new system. For the needs of engineering, it is necessary to divide these processes into stages with typical characteristics. Each stage has different goals and working methods, and the tasks in the stages are also responsible for different types of personnel. This process is called the life cycle of the information system.
Software is a relatively complex component in an information system, and the life cycle of software can be used to represent the life cycle of an information system. The software life cycle usually includes: feasibility analysis and project development plan, requirements analysis, outline design, detailed design, coding, testing, maintenance and other stages.