Thinking in Systems

Purposes are deduced from behavior, not from rhetoric or stated goals.

这就是我为什么讨厌这种无力的解释：“某X设计的意图是解决Y问题”。实际运作起来效果如何，副作用如何，恐怕都不在考虑之内。只要开头的口号喊得足够响亮就对了。

12. Numbers--Constants and parameters such as subsidies, taxes, standards

...Changing these variables rarely changes the behavior of the economy system. ...These kinds of critical numbers are only nearly as common as people seem to think they are. Most systems have evolved or are designed to stay far out of range of critical parameters. Mostly, the numbers are not worth the sweat put into them.

11. Buffers--The sizes of stabilizing stocks relative to their flows10. Stock-and-flow Structures--Physical systems and their nodes of intersection

Often physical rebuilding is the slowest and most expensive kind of change to make in a system. Some stock-and-flow structures are just plain unchangeable.

9. Delays--The lengths of time relative to the rates of system changes

A delay in a feedback process is critical relative to rates of change in the stocks that the feedback loop is trying to control. ...A system just can't respond to short-term changes when it has long term delays. That's why a massive central-planning system, such as the Soviet Union or General Motors, necessarily functions poorly. ...It's usually easier to slow down the change rate, so that inevitable feedback delays won't cause to so much trouble. That's why growth rates are higher up on the leverage point list than delay times.

8. Balancing Feedback Loops--The strength of the feedbacks relative to the impacts they are trying to correct

Any balancing feedback loop needs a goal, a monitoring and signaling device to detect deviation from the goal, and a response mechanism.

7. Reinforcing Feedback Loops--The strength of the gain of driving loops

Reducing the gain around a reinforcing loop--slowing the growth--is usually a more powerful leverage point in systems than strengthening balancing loops, and far more preferable than letting the reinforcing loop run.

6. Information Flows--The structure of who does and does not have access to information

Missing information flows is one of the most common causes of system malfunction. Adding or restoring information can be a powerful intervention, usually much easier and cheaper than rebuilding physical infrastructure.

5. Rules--Incentives, punishments, constraints

If you want to understand the deepest malfunctions of systems, pay attention to the rules to who has power over them.

4. Self-organization--The power to add, change, or evolve system structure

Self-organization means changing any aspect of system lower on this list...The ability to self-organize is the strongest form of system resilience. A system that can evolve can survive almost any change, by changing itself. Self-organization is basically a matter of an evolutionary raw material--a highly variable stock of information from which to select possible patterns--and a means for experimentation, for selecting and testing new patterns.

3. Goals--The purpose or function of the system2. Paradigms--The mind-set out of which the system--its goals, structure, rules, delays, parameters--arises

The shared idea in the minds of society, the great big unstated assumptions, constitute that society's paradigm, or deepest set of beliefs about how the world works. These beliefs are unstated because it is unnecessary to state them--everyone already knows them. So how do you change paradigms? You keep pointing at the anomalies and failures in the old paradigm. You keep speaking and acting, loudly and with assurance, from the new one. You insert people with the new paradigm in places of public visibility and power. You don't waste time with reactionaries; rather, you work with active change agents and with the vast middle ground of people who are open-minded.

1. Transcending Paradigms

System consists of elements, interconnections and purpose(for human)/function(nonhuman).

You think that because you understand "one" that you must therefore understand "two" because one and one make two. But you forget that you must also understand "and". - Sufi teaching story

about Teaching Stories: http://en.wikipedia.org/wiki/Teaching_stories Sufi is related to Islam.

From "the blind man and the matter of the elephant":

Each had felt one part out of many. Each had perceived it wrongly... The behavior of a system cannot be known just by knowing the elements of which the system is made.