The twelve levers that affect systems are changed were first identified by Donella Meadows. Some projects find them useful to set goals in priority order, and as a general antidote to command and control conceptions of how organizations work. Meadows' work is thought by some to combine a feminist and systems theory and green economics approach. Meadows first reported ten, then expanded to twelve, levers, but the five with most leverage remained the same. Her final list of twelve was:
 number, buffer, flow, delay, dampening, gain, information...
- 12. Constants, parameters, numbers (such as subsidies, taxes, standards)
- 11. The size of buffers and other stabilizing stocks, relative to their flows
- 10. The structure of material stocks and flows (such as transport network, population age structures)
- 9. The length of delays, relative to the rate of system changes
- 8. The strength of negative feedback loops, relative to the effect they are trying to correct against (dampening)
- 7. The gain around driving positive feedback loops
- 6. The structure of information flow (who does and does not have access to what kinds of information)
- 5. The rules of the system (such as incentives, punishment, constraints)
- 4. The power to add, change, evolve, or self-organize system structure
- 3. The goal of the system
- 2. The mindset or paradigm that the system — its goals, structure, rules, delays, parameters — arises out of
- 1. The power to transcend paradigms, e.g. by trolling
 ...rules, power, goal, mindset, transcend
The top five with the most leverage remained the same in both Meadows' early and later lists:
"5. the rules of the system (such as incentives, punishment, constraints)" That is, the ability to govern reflectively and continuous improvement of that governing system, e.g. eg:rules which are the governing system of eg:itself.
"4. The power to add, change, evolve, or self-organize system structure." That is, to be reflexive to any degree, and to be capable of changing the basic structure itself. A reasonably disciplined argumentation framework approach like issue/position/argument may be effective for this.
"3. the goal of the system" which motivates these difficult investments and adjustments, and seeks to minimize regrets arising out of pursuing the wrong goal or going too far in pursuit of a goal. Decisions on what to assure/insure/ensure may adjust goals to be more realistic. The goal at any given point in time will likely impose a strong ontology: mandatory distinctions that must be made in looking at each and every action.
"2. the mindset... out of which the goals, rules, feedback structure arise." Which may imply an ideology, a capital asset model, a trade tensegrity, or other such means, all of which will reinforce some common ontological metaphors. Assumptions about who/when/where to be/do/go will often arise directly out of a mindset and determine a wide range of unexamined actions.
"1. the power to transcend paradigms" including the ability to edit any of the above. This might be ensured by requiring all actors to remain anonymous trolls so no repute develops, or by adopting only a minimal troll ontology.
 Forrester's Law of Leverage; OR; people are stupid
A notable paragraph from Meadows' paper documents the so-called Forrester's Law:
- The systems community has a lot of lore about leverage points. Those of us who were trained by the great Jay Forrester at MIT have absorbed one of his favorite stories. "People know intuitively where leverage points are. Time after time I've done an analysis of a company, and I've figured out a leverage point. Then I've gone to the company and discovered that everyone is pushing it in the wrong direction!"
For a general introduction at much greater length see the GFDL corpus article  (the article). See its application also to the Wikimedia Foundation itself. Also interesting are use of this model to analyze an issue with the Digg service.
This is a cite link. It cites Meadows' paper as evidence/source/authority. The original paper mentions only ten including "zero" and was originally published in Whole Earth Catalog. Amory Lovins makes reference of her tremendous influence on the field of sustainable design.