A System is defined as a set of interrelated components that work together to achieve common goals, accepting input data (input) and producing results (output) in an organized transformation processes.
Self-regulation describes the ability of a system to ‘manage’ itself (feedback) towards its purpose or goals despite environmental disturbances based on ether balancing or reinforcing feedback:
- First order feedback whereby the goal is determined externally to it
- Second order feedback where system is capable of choosing between variety responses to environmental changes in order to achieve its goal
- Third order system is one that is capable of changing the goal state itself in response to feedback process determining the goal internally s opposed to externally
The properties of the whole are superior to and different from combined properties of the parts.
A system consists of the following functions:
Input and Output
- Involve collection / acquisition and assembly of the elements that enter the system to be processed.
- Example: raw materials, energy, human effort are basic components of the production system;
Processing (Processor operations)
- Involves the transformation process which converts the input data into a finished product
- The result of the transformation process, for example, the finished product or service
- What control a process
- Working procedure
- Resources used for the conversion process
- Equipment and facilities
- Customer, vendors, controlling authorities, competitors
- Is the return or influence the outputs cause the entrances to balance the functioning of the system
The feedback mechanism is a communication between the output and the system input and the main functions of feedback is to control the systems output, maintain the balance and survival.
Feedback is a method of controlling a system by reinserting into it the result of its past performance (Norbet Wiener).
Feedback key propose is also to ensure homeostatic balance: maintaining stability. Negative feedback is a central homeostatic and cybernetic concept, referring to how an organism or system automatically opposes any change imposed upon it. Negative feedback arises out of balances between forces and factors that mutually influence each other. To illustrate several of its important characteristics, we can regard a car and its driver as a unified, complex, homeostatic or “goal-seeking” system in that it seeks to keep the car moving on track.
Oscillation is a common and necessary behavior of many systems whereby abrupt negative feedback, however, usually over-corrects. A negative feedback, if it is as large as the disturbance that triggered it, may become an impressed change in the direction opposite to that of the original disturbance. Negative feedback takes time and such a time lag is an essential feature of many natural systems. This may set the system to oscillating above and below the equilibrium level.
A feedback loop where the outputs of a process are available as causal input to that process. The causal input (cause and effect of related elements) influencing the process. The influence can either be reinforcing (positive) or balancing (negative).
Feedback loops control a system’s major dynamic behavior. A feedback loop is a series of connections causing output from one part to eventually influence input to that same part. This circular flow results in large amplification, delay, dampening effects, which is what causes the gross behavior of the system. Every part is involved in one or more feedback loops. Systems have more feedback loops than parts, which causes unimaginable complexity. Feedback loops are the main reason a system’s behavior is emergent.
Systems contains only two kinds of feedback loops: reinforcing and balancing, also called positive and negative feedback loops. Complex systems are typically composed of multiple interacting feedback loops: some negative some positive.
Positive feedback result in escalation/growth while negative feedback result equilibrium/homeostasis and oscillation.
A feedback loop occurs when a change in something ultimately comes back to cause a further change in the same thing. If the further change is in the same direction it’s a positive or reinforcing loop. If it’s in the opposite direction it’s a negative or balancing loop, also called a goal-seeking loop.
Understanding Feedback Characteristics enables efficient design of feedback:
- Increasing returns
- A small change is amplified not corrected by feedback
- Changes grow without limit until some other factor intervenes
- Pairs of positive feedback systems can oscillate between two unstable states
- Interest rates
- Birth rate
- Control Information
- Information about what has been achieved in the output is fed back to allow the process to be tuned
- Without this information no learning or improvements can take place over time
- The cost and energy involved feedback effect the efficiency of the system
- Within social process feedback has to be interpreted
- Only reasonably linear processes benefit from simple feedback
- Discontinuation in system behavior may be more important than continuous
- Control Information
Gain and Delay
- Delay : The delay that is introduced between the output to when its feedback into the input. Long delay creates system instability so that it cannot be controlled by its mechanisms impacting resilience. Medium delay produces oscillations while short delay gives smooth response converging on the desired output.
- Gain : The gain of negative feedback process is the scale of the version of the output fed back into input
- Process Control: Information from downstream process is fed back upstream. From simple input-process-output model measure the output and compare with desired output values. Use the feedback to adjust the input for subsequent process
- Mechanical – thermostat controlling a central heating system
- Economics – Equilibrium of supply and demand via price
Goal directed behavior
- Establish the goals
- Establish set of measure or observations that indicate progress towards the goal
- Verify what has been achieved in achieving the goal
- If necessary change the goal or change the measure
- Carry-out actions that converge towards the goal
- Central heating system
- Targets in managing the economy
- Establish the goals
- Useless Controls
- Control action that only seem to produce the required behavior
- Control action working against the logic of the system (its purpose)
- Control actions that are subverted by other actors in the system
- Subtle intervention
- Adjustment or additions simple rules (variety amplifies)
- Making the connections between actions and system purpose more transparent
- Useless Controls
- The behavior of the system cannot be predicted on the basis of the behavior of the elements
- Intervention in the system have inherently unpredictable outcomes
- If individuals or their organization is incapable of associating effects with their causes then learning and adaptation is not possible and both will continue repeating same errors
Causal Relationship related to Feedback Using System Model
According to this model the function of price in a market system is as follows:
- It is an effect of given relationship between Supply and demand
- At the same time it is a causal relationship the levels of supply and demand
Thus sometime the market forces have the effect of balancing supply and demand and stabilizing prices.
Understanding the limitation of system model:
- Sometimes difference in prices are not reflect to changes to demand and supply
- It can be elastic: responds quickly
- Inelastic : responds weakly, slowly or not at all
- Sometimes changes in supply and demand are not reflected in the prices
- Sometimes there are other systemic stuff (market turbulence) going on that the effects of market forces are obscured
According to Goetz, a feedback loop involves four stages:
- the data, a behavior or evidence.
- relaying the information to the person in a context that makes it emotionally resonant or relevance.
- the paths ahead the information illuminates, or consequence.
- the moment when the individual can recalibrate a behavior, and take action.
Feedback cannot influence the past but only the future: therefore feedback design must consider those transformation processes that that need to be adjusted to achieve desired objectives.