Feedback, in general terms is a measure to evaluate the system so that it adapts to improve. This very behavior of adaption, inspired by nature has found significant impact on the systems which are being implemented. Adaption can be built around negative feedback in order to stop the behavior or positive feedback in order to reinforce the behavior.
It is quite common to see manufacturing units implementing the production process using feedback control. Feedback here serves the purpose of monitoring and fine tuning the product. With emerging hardware, software and automated solutions, the feedback based system has given birth to different domain in engineering called control theory.
Control systems are most often based on the principle of feedback, whereby the signal to be controlled is compared to a desired reference signal and the discrepancy used to compute corrective control action. Striking developments have taken place since 1980 in feedback control theory. The subject has become both more rigorous and more applicable. Ottino advises engineering to be center of these developments to contribute new theories and tools to the field.
Two main difficulties identified in applying control theory to software systems is:
- One being developing mathematical models of software behavior suitable for controller design and
- Other lack of software engineering methodologies for pursuing controllability as a first class concern.
Often there is no clear separation between the controller, the process and the other elements of the system.
One of the major research areas is the requirement for newer approaches for architecture and design.