Elements of a System
The important elements of a system are;
- Output and Inputs
- Processor(s)
- Control
- Feedback
- Environment
- Boundaries and Interface
Outputs and Inputs
A major objective of a system is to produce an output that has value to its user. Whatever the nature of the output, it must be within the line with the explanations of the intended user. Inputs are the elements that enter the system for processing. Output is the outcome of processing. A system feeds on input to produce output in much the same way that a business brings in human financial, and material resources to produce goods and services. It is important to point out here that determining the output is a first step in specifying the nature, amount and regularity of the input needed to operate a system. For example in systems analysis, the first concern is to determine the user’s requirements of a proposed commuter system — that is specification of the output that the computer is expected to provide for meeting user requirements. Input and processing design follow:
Processor(s)
The processor is the element of a system that involves the actual transformation of input into output. It is the operational component of the system. Processor may modify the input totally or personally, depending on the specifications of the output. This means that as the output specifications change so does the processing. In some cases, input is also modified to enable the processor to handle the transformation.
Control
The control element guides the system. It is the decision — making sub-system that controls the pattern of activities governing input, processing and output. In an organizational context, management as a decision making body controls the inflow handling and outflow of activities that affects the welfare of the business. Output specification determine, what and how much input is needed to keep the system in balance.
In system analysis, knowing the attitudes of the individuals who control the area for which a computer is being considered can make a difference between the success and the failure of the installation. Management support is required for securing control and supporting the objective of the proposed change.
Feedback
Control in a dynamic system is achieved by feedback. Feedback measures output against standard in some form. After the output is compared against performance standards, changes can result in the input or processing and consequently, the output.
Feedback may be positive or negative, routine or informational. Positive feedback reinforces the performance provides the controller with information for action. In system analysis, feedback is important in different ways. During analysis, the user may specify that the problems in a given application, and justify the need for change. Another form of feedback comes after the system is implemented. The user informs the analyst about the performance of the new installation. This feedback often results in enhancements to meet the user’s requirements.
Environment
The environment is the “super system” within which an organization operates. It is the source of external elements that unhinge on the system. In fact, it often determines how a system must function. The organization’s environment, consisting of vendors, competitions and others, may provide constraints and consequently influence the actual performance of the business.
Boundaries and Interface
A system should be defined by its boundaries — the limits that identify its components, processes and interrelationships and interfaces with another system. For example, a teller system in a commercial bank is restricted to the deposits, withdrawals and related activities of customers checking and savings accounts. It may exclude mortgage foreclosures, trust activities and the like.
Each system has boundaries that determine its sphere of influence and control. Although in an integrated banking computer system design, a customer who has a mortgage and a checking account with the same bank may write a check through the “teller system” to pay the premium that is latter processed by the “mortgage loan system”. Recently system design has been successful in allowing the automatic transfer of funds from the bank account to pay bills and other obligations to creditors, regardless of distance or location. This means that in systems analysis, knowledge of the boundaries of given system is crucial in determining the nature of its interface with other system for successful design.