feedback loop

A feedback loop includes monitor, comparator, adjust and feedback. In the feedback loop, you look (monitor) at the information - feedback - that you are getting from a system. Using this, you compare the output with the input and make adjustments.

The feedback loop is the most basic information flow and should be determined (in domain analysis) or defined (in systems design) before mapping any other information flow. A systems diagram usually serves this purpose.

A causal loop diagram is the most abstract description of a feedback loop, describing literally "what feedback causes what additional feedback". If the feedback is increasing over time it is called positive feedback. If it is decreasing to stability it is called negative feedback. The terms "positive" and "negative" do not refer to the desirability of the feedback, only to its magnitude. That is, saying something emotionally negative to someone that aggravates a sitaution is positive feedback, and saying something emotionally positive that has the effect of stabilizing a situation is called negative feedback.

In management science, a critical path or critical chain is where feedback loop analysis usaully begins. For instance, throughput accounting applies critical chain todecision making and value creation - what matters is not the "labor efficiencies" but overall time, energy, money and attention savings. The continuous improvement of all processes using the creative component - individual capital - is the major source of reductions in the total cost of operations. It is very advanced activity-based costing in which labour is assumed to perform risk management - a model very compatible with workplace democracy. The feedback loops between work and decisions are assumed to be very tight. Most quality management methodologies, e.g. those of William H. Deming, apply a similar approach.

This is a refer link - the basic concept is related as defined in New York State Standard MST 5.4. More advanced concepts are described based on various GFDL corpus sources.