Chapter Two: A Brief Visit to the Systems Zoo
“The goal of all theory is to make the basic elements as similar and as few as possible without having to surrender the adequate representation of experience.”
Like a zoo, conceptual systems allow us to see real events and resources in neat, understandable terms, separating elements and driving factors from one another as well as their natural environments, in order to observe their most innate behaviors.
One Stock-Systems:
-Often a system is made up of multiple loops—balancing or reinforcing—each dragging a “stock” (some measurable resource) in various directions.
-The thermostat, for example, is governed by a reinforcing loop (the furnace, or heating loop) and a balancing loop (an invariably flawed insulation that allows heat to leak out).
-Predicting the activity of system means taking into account the leakages and balancing loops within a system. It’s like trying to keep a bucket full, when there’s a hole in the bottom letting out what’s being added in. Inflow must be set to perform above the desired outcome depending on the force of the balancing loop that opposes it.
Delays
“The information delivered by a feedback loop can only affect future behavior; it can’t deliver the information, and so can’t have an impact fast enough to correct behavior that drove the current feedback.“
In every system, there are delays in perception, response and delivery. Perception delays refer to the time it takes for needs to be recognized; response delays represent the time it takes for action to be taken from when the need is recognized; and delivery delay is the time is takes for the desired outcome of the response to occur. Each must be taken into account in order for a system to be accurately modeled and to reasonably manage inflow and outflow. There will always be delays in responding.
There is also far more attention given in this chapter to “delays” than is represented in the notes. According to the author, system malfunction tends to revolve around misunderstanding of delays and the forces underlying them.
Determinants of System Behavior
The way systems behave depends on what happens to the driving variables. When establishing a model of system, questions to ask:
1) Are the driving factors likely to unfold this way?
2) If they did would the system react this way?
3) What is driving the driving factors?
System studies are not typically intended to predict the future; rather, they predict what will happen given a specific set of circumstances or changes in the environment.
Summary:
Your mental model of a system needs to include all the important flows and elements, or you will be surprised by the system’s behavior. The “trick” of systems design is to recognize what structures contain which latent behaviors, and what conditions release those behaviors—and, where possible, to arrange the structures and conditions to reduce the probability of destructive behaviors and to encourage the possibility of beneficial ones.
Connections to health care:
This chapter focuses primarily on the interrelatedness of the elements within systems, and how a the most accurate model of system—one which optimally conceptualizes its interrelations—will allow one to properly predict, harness, and possibly even redirect the system’s behavior. It seems that acknowledging this would prompt a health systems planner or administrator to not only think more deeply about the interconnectedness of departments within the hospital—or whatever “health system” is in question—but also to consider what the driving forces are which impact the flow of patients into and out of the hospital, and what forces are driving those driving forces. Of course, the driving forces and their driving forces are not only difficult to pinpoint, they are often in flux and subject to ever changing socio-cultural or environmental conditions. I assume future chapters will deal with the problem of how to conceptualize, control and/or reform increasingly complex systems of relationships between elements.
