Thinking In Systems | A Primer by Donella H. Meadows, Diana Wright

I. Brief Summary

An essential primer on systems thinking which can help better understand the biggest problems we are facing in the world. They cannot be solved in isolation. Everything we see, do and experience in this world is made of systems. Why is it important to understand systems? Doing so will enable us to help them function better and identify when a broken system is in need of repair.

II. Big Ideas

• What is a system?
  • A system is a set of things—people, cells, molecules, or whatever—interconnected in such a way that they produce their own pattern of behavior over time.
  • A system is an interconnected set of elements that is coherently organized in a way that achieves something.
  • A system must consist of three kinds of things: elements, interconnections, and a function or purpose.
  • A system is more than the sum of its parts. It may exhibit adaptive, dynamic, goal-seeking, self-preserving, and sometimes evolutionary behavior.
  • A system is composed of stocks (quantities measured at a specific moment in time) and flows (change over time).
  • A complex system is more than just the sum of its parts.
  • Feedback loops are where changes in stock affects the flow in/out of the same stock. There can be “balancing” feedback loops that have a regulatory, stabilizing behavior, and “re-enforcing” feedback loops that snowballs into an avalanche in the direction of change (positive or negative).
• Why do systems work so well? Because of the following characteristics:
  • Resilience: is a major determining factor in a system’s ability to adapt to changing conditions because it is a system’s elasticity, or how well it recovers from a transition. The resilience of any given system is a product of its structure as well as its feedbacks.
  • Self-organization: some can also self-organize. That means they can learn, diversify, evolve and build on their own structure.
  • Hierarchy: reduce the level of information any given part of the system has to handle. For example, since liver cells know how to decompose toxins, lung cells don’t need to.
• Systems often have the property of self-organization—the ability to structure themselves, to create new structure, to learn, diversify, and complexity. Even complex forms of self-organization may arise from relatively simple organizing rules—or may not.
• Systems thinkers see the world as a collection of stocks along with the mechanisms for regulating the levels in the stocks by manipulating flows.
• Stop looking for who’s to blame; instead you’ll start asking, “What’s the system?” The concept of feedback opens up the idea that a system can cause its own behavior.
  • Hunger, poverty, environmental degradation, economic instability, unemployment, chronic disease, drug addiction, and war, for example, persist in spite of the analytical ability and technical brilliance that have been directed toward eradicating them. No one deliberately creates those problems, no one wants them to persist, but they persist nonetheless. That is because they are intrinsically systems problems—undesirable behaviors characteristic of the system structures that produce them. They will yield only as we reclaim our intuition, stop casting blame, see the system as the source of its own problems, and find the courage and wisdom to restructure it.
  • Before you disturb the system in any way, watch how it behaves.
• A change in purpose changes a system profoundly, even if every element and interconnection remains the same.
• The least obvious part of the system, its function or purpose, is often the most crucial determinant of the system’s behavior.
• 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.
• Many of the interconnections in systems operate through the flow of information. Information holds systems together and plays a great role in determining how they operate.
• Stocks usually change slowly. They can act as delays, lags, buffers, ballast, and sources of momentum in a system.
• A feedback loop is a closed chain of causal connections from a stock, through a set of decisions or rules or physical laws or actions that are dependent on the level of the stock, and back again through a flow to change the stock.
  • There are different kinds of feedback. If a flow stabilizes the difference between the actual and desired levels of stock then it’s known as balancing feedback. There is another kind of feedback loop which is known as reinforcing feedback, which generates more or less of what already exists.
  • In physical, exponentially growing systems, there must be at least one reinforcing loop driving the growth and at least one balancing loop constraining the growth, because no physical system can grow forever in a finite environment.
  • The balancing feedback loop that should keep the system state at an acceptable level is overwhelmed by a reinforcing feedback loop heading downhill. The lower the perceived system state, the lower the desired state. The lower the desired state, the less discrepancy, and the less corrective action is taken. The less corrective action, the lower the system state. If this loop is allowed to run unchecked, it can lead to a continuous degradation in the system’s performance.
  • The more output that is produced, the more can be invested to make new capital. This is a reinforcing loop, like the birth loop for a population. The investment fraction is equivalent to the fertility. The greater the fraction of its output a society invests, the faster its capital stock will grow.
  • Every balancing feedback loop has its breakdown point, where other loops pull the stock away from its goal more strongly than it can pull back.
• All systems share common features, but some of them can produce extremely unnatural and even problematic behavior. This can happen when the individual subsystems each have a different goal, and it’s called policy resistance. If one actor within a system or any of its subsystems gets the upper hand and uses it to shift the system’s direction, all the others will have to work twice as hard to pull it back in line. The result is a system that looks stuck, reproducing the same problems over and over again. For instance, drug traffickers and addicts both want drug supplies to be high, but police want the opposite.
• The central question of economic development is how to keep the reinforcing loop of capital accumulation from growing more slowly than the reinforcing loop of population growth—so that people are getting richer instead of poorer.
• A diverse system with multiple pathways and redundancies is more stable and less vulnerable to external shock than a uniform system with little diversity.
• Most of what goes wrong in systems goes wrong because of biased, late, or missing information.

III. Quotes

• We can’t control systems or figure them out. But we can dance with them!
• If we’re to understand anything, we have to simplify, which means we have to make boundaries.
• We don’t talk about what we see; we see only what we can talk about.
• 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.”
• Remember, always, that everything you know, and everything everyone knows, is only a model. Get your model out there where it can be viewed. Invite others to challenge your assumptions and add their own.
• There are no separate systems. The world is a continuum. Where to draw a boundary around a system depends on the purpose of the discussion.
• We can't impose our will on a system. We can listen to what the system tells us, and discover how its properties and our values can work together to bring forth something much better than could ever be produced by our will alone.
• Let's face it, the universe is messy. It is nonlinear, turbulent, and chaotic. It is dynamic. It spends its time in transient behavior on its way to somewhere else, not in mathematically neat equilibria. It self-organizes and evolves. It creates diversity, not uniformity. That's what makes the world interesting, that's what makes it beautiful, and that's what makes it work.
• No one can define or measure justice, democracy, security, freedom, truth, or love. No one can define or measure any value. But if no one speaks up for them, if systems aren’t designed to produce them, if we don’t speak about them and point toward their presence or absence, they will cease to exist.
• Addiction is finding a quick and dirty solution to the symptom of the problem, which prevents or distracts one from the harder and longer-term task of solving the real problem.
• If you define the goal of a society as GNP, that society will do its best to produce GNP. It will not produce welfare, equity, justice, or efficiency unless you define a goal and regularly measure and report the state of welfare, equity, justice, or efficiency.
• You can drive a system crazy by muddying its information streams.
• We know a tremendous amount about how the world works, but not nearly enough. Our knowledge is amazing; our ignorance even more so. We can improve our understanding, but we can't make it perfect.
• Managers do not solve problems, they manage messes. — Russell Ackoff
• Because of feedback delays within complex systems, by the time a problem becomes apparent it may be unnecessarily difficult to solve. — A stitch in time saves nine.
• 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.
• Once you start listing the elements of a system, there is almost no end to the process. You can divide elements into sub-elements and then sub-sub-elements. Pretty soon you lose sight of the system. As the saying goes, you can’t see the forest for the trees.
• The system, to a large extent, causes its own behavior! An outside event may unleash that behavior, but the same outside event applied to a different system is likely to produce a different result.
• Storing information means increasing the complexity of the mechanism.
• Self-organization is often sacrificed for purposes of short-term productivity and stability. Productivity and stability are the usual excuses for turning creative human beings into mechanical adjuncts to production processes. Or for narrowing the genetic variability of crop plants. Or for establishing bureaucracies and theories of knowledge that treat people as if they were only numbers.
• I have yet to see any problem, however complicated, which, when looked at in the right way, did not become still more complicated.
• The world is nonlinear. Trying to make it linear for our mathematical or administrative convenience is not usually a good idea even when feasible, and it is rarely feasible.
• Loss of resilience can come as a surprise, because the system usually is paying much more attention to its play than to its playing space.
• There always will be limits to growth. They can be self-imposed. If they aren’t, they will be system-imposed.
• Everyone understands that you can prolong the life of an oil-based economy by discovering new oil deposits. It seems to be harder to understand that the same result can be achieved by burning less oil. A breakthrough in energy efficiency is equivalent, in its effect on the stock of available oil, to the discovery of a new oil field—although different people profit from it.
• President Jimmy Carter had an unusual ability to think in feedback terms and to make feedback policies. Unfortunately, he had a hard time explaining them to a press and public that didn’t understand feedback.
• Hierarchical systems evolve from the bottom up. The purpose of the upper layers of the hierarchy is to serve the purposes of the lower layers.
• Remember—all system diagrams are simplifications of the real world.
• The more I practice piano, the more pleasure I get from the sound, and so the more I play the piano, which gives me more practice.
• If the desired system state is good education, measuring that goal by the amount.
• In the end, it seems that mastery has less to do with pushing leverage points than it does with strategically, profoundly, madly, letting go and dancing with the system.
• Resilience is a measure of a system’s ability to survive and persist within a variable environment. The opposite of resilience is brittleness or rigidity.
• Mental flexibility—the willingness to redraw boundaries, to notice that a system has shifted into a new mode, to see how to redesign structure—is a necessity when you live in a world of flexible systems.