The Fundamentals of Systems Theory
As Peter Senge famously said, "If you split an elephant in two, you don't get two elephants."[1]
This captures the essence of systems thinking—a perspective for seeing reality as made up of wholes. It's built on holism, where the whole cannot be understood by breaking it into its constituent parts.
The systems paradigm places emphasis on the relationships between elements rather than the elements themselves. This is fundamentally different from the Newtonian view, which is linear and relies on analysis—breaking things apart—to understand them.
By focusing on interrelations, our whole perspective on reality shifts. Think about an organisation. You can't understand it by studying each employee in isolation. You need to see how they connect, communicate, and collaborate.
What is a System?
Russell Ackoff defined it best:[2]
A system is a whole consisting of two or more parts where each can affect the whole, none can have an independent effect on the whole, and no subgroup can have an independent effect on the whole. A system is a whole that cannot be divided into independent parts.
In simpler terms: a system has distinct components that are interdependent, engaged in non-linear interactions through feedback mechanisms, forming a unified whole that serves a purpose.
Two strangers sitting in a park aren't a system—they're just an aggregate. A married couple is a system: their combined efforts produce outcomes greater than the sum of their individual contributions. They adapt to each other, creating dynamic patterns over time.
The Core Concepts
Interdependence
Every system hinges on interdependence between its parts. Rather than independent entities lumped together, a system is a coherent structure woven by threads of mutual reliance.
When interdependent parts combine, they create something greater through emergence. The whole becomes more than the sum of its parts.
Without interdependencies, a healthcare system would dissolve into isolated silos—specialists who never talk, records that don't connect, patients falling through cracks.
High differentiation with low integration produces dysfunction.[3] The parts might be excellent individually, but the system fails.
Feedback
Feedback is the circular flow of influence within a system. Causes become effects, which become causes again.
Think in circles, not lines.
A patient gets angry in a waiting room. The receptionist gets defensive. The patient gets angrier. The receptionist gets more defensive. On and on. What looked like a simple cause (long wait) is actually part of a loop.
Reinforcing Feedback
Reinforcing feedback amplifies change. It accelerates growth or decline. These loops can be virtuous (success breeds success) or vicious (failure breeds failure).
Bank runs work this way: a few people withdraw money, others hear about it and panic, more withdrawals happen, more panic spreads. A small initial trigger spirals into collapse.
Balancing Feedback
Balancing feedback restores equilibrium. Your body's temperature regulation is the classic example: too hot, you sweat; too cold, you shiver. The system pushes back toward a set point.
In organisations, balancing feedback can resist change—even beneficial change. A clinical lead tries to reduce burnout, but hits resistance from a "work harder" culture. The system maintains its status quo.
Delay
Delay is the time lag between action and result. It's present in every feedback loop, and it causes trouble when we don't account for it.[4]
Hire someone today, they're productive in six months. Launch a policy today, results show up next year. The delay makes us impatient. We overcorrect. We add more interventions before the first one has had time to work.
Types of delay:
- Physical: Moving things from A to B
- Transactional: Administrative processes
- Informational: Data transfer and processing
- Perception: Reality changing faster than we can recognise[5]
Purpose
Every system orients toward a purpose—explicit or implicit, recognised or hidden, stable or shifting.
In complex social systems, this gets messy. Different actors have different goals. A healthcare system is simultaneously:
- A profit system for private providers
- A distribution system for pharma
- An employment system for workers
- A policy system for government
- A training system for students
When purposes compete, the system generates massive negative synergies. Understanding whether stakeholder purposes align or conflict is crucial for effective intervention.
This concept of "multi-finality" was highlighted in the WHO's landmark report on systems thinking in health.[6]
Boundaries and Context
Systems are nested within other systems, framed by boundaries, and shaped by their surrounding environment.
Self-Similarity
Organisations are both wholes and parts. A hospital is a whole (containing departments, staff, equipment) and a part (of a regional health system, which is part of a national system).
Complexity occurs at every level. Systems leadership isn't about being at the top—it must be applied throughout.
The Boundary Problem
Donella Meadows wrote:[7]
"Systems rarely have real boundaries. There are only boundaries of word, thought, perception and social agreement. We have to invent boundaries for clarity and sanity, and boundaries can produce problems when we forget that we've artificially created them."
The right boundary for thinking about a problem rarely matches academic or political boundaries. COVID-19 showed this clearly—the virus ignored national borders entirely.
The challenge is staying creative enough to drop boundaries that worked for the last problem and find appropriate ones for the next.
Environment
A system cannot be understood without understanding its environment. The environment provides inputs, absorbs outputs, and shapes what's possible.
A biological system interacts with nature. A political institution operates within laws, norms, and power structures. And sometimes these environments conflict—as when COVID's biological reality clashed with political boundaries and policies.
Where to Go From Here
This is just the foundation. Systems thinking requires practice—learning to see loops instead of lines, relationships instead of things, patterns instead of events.
Start noticing feedback in your daily life. Ask what purpose a system serves—and for whom. Question where you're drawing boundaries.
The elephant, after all, only makes sense as a whole.