The general systems model is used to represent a broad explanation of the system (or any of its subsystems) to which more concrete details can be added as needed.
The principal phases of a system (open) are:
a. Input - the first phase of any system in which data, labor and other energy, materials, equipment, and money are received from another system. Examples: raw materials, skills needed by a word processing operator
b. Transformation Process changes or transforms input into desired form.
Eg.: sorting, storing, retrieving, and computing.
c. Output is the ultimate goal of a system, that which results after the input has been changed in some way during the second phase - transformation process to a desired form. Eg: correspondence, reports, accounting statements, budgets.
d. Feedback is the regulating force that compares the systems output with the standards of performance set for the system. Eg. Customer evaluation of service.
e. Control is the systems phase that dictates what can and cannot be done in each of the other phases of the AOS. Controls are placed over the input, transformation process, output and feedback phases.Eg. Plans, procedures, programs, and standards of employee performance.
Systems Structure (or systems hierarchy) is somewhat related to the structure appearing on the organization chart. It evolves as the form of organization for providing a wide variety of systems services to the firm.
a. Total System-Subsystems Relationship - Total system is made up of many major systems. Each of these major systems is, in turn, divided into a number of subsystems. - When all of these systems are combined into a total system, they form a company-wide information network. All three levels of system total, major, and subsystem have the same general makeup and follow the same operating phases.
b. Information Systems - The information function operates through a system that controls the many activities making up the information cycle. The major system is an information system and total set is the management information system. At the heart of such as a system is the computer, which performs many of the functions of the information cycle.
c. Database - A database is a central master file containing company-wide information from the major systems of the firm. collection of information from such areas as accounting, engineering, marketing, human resources, production, and R & D in one large computerized library. It also provides organization-wide access to the master file via computer terminals. Information is captured and stored only once. Total file space is reduced since duplicate files can be eliminated. Updating of files is facilitated as transactions come into the system at one point only. Database uses large computers or small networked computers to provide additional storage power. Departments or individuals are reluctant to release certain information to a centralized unit because they fear unauthorized access to the files or accidental destruction or removal of the stored information. Passwords that limit access to data have lessened this fear.