This is the eighth article in my 8-week series exploring foundational systems thinking concepts, written for the 2025 RE-AMP Systems Thinking Academy. Whether you’re following along with the series or diving deep into systems practice, this article explores the CDE Model — Containers, Differences, and Exchanges — the underlying dynamics that shape every complex adaptive system. Learn more about the Academy and register here.
The CDE Model: Containers, Differences, and Exchanges
In Articles 5 through 7, we explored the two meta-approaches of Human Systems Dynamics (HSD): Adaptive Action and Pattern Logic. Adaptive Action slows the rush from perception to action. Pattern Logic shifts our attention from isolated parts to patterns of relationship and flow. Together, they give us a way of participating more consciously in the dynamics of Complex Adaptive Systems (CAS).
Now we add a third foundational piece of HSD: the CDE Model — Containers, Differences, and Exchanges. This model describes the underlying conditions that shape patterns in all CAS. It gives us a way to understand how patterns form, how they shift, and how we can influence them.
Conditions That Shape Patterns
In complex systems, we can’t predict or control specific outcomes. But we can pay attention to the conditions that shape how patterns emerge. The CDE Model identifies three:
- Containers: The boundaries that hold the system together. These might be physical (a room, a watershed), organizational (a team, a coalition), cultural (shared norms, identity), or even virtual (an online platform). Containers define who/what is “in” and “out,” and provide coherence for interaction.
- Differences: The diversity within the container. Differences might include perspectives, roles, resources, identities, or priorities. Differences create the tension and possibility for new patterns to emerge. Too little difference, and systems stagnate. Too much unmanaged difference, and systems fragment.
- Exchanges: The flows of information, energy, and resources among agents. Exchanges may be conversations, financial flows, feedback signals, or material exchanges. They are the means by which differences interact inside the container.
Patterns in complex systems emerge through the interplay of these three conditions.
Examples of CDE in Action
Consider a grassroots coalition forming to respond to climate change:
- The container might be the coalition itself, bounded by membership and purpose.
- The differences might include varied geographies, strategies, and cultural perspectives.
- The exchanges are the meetings, communications, and joint projects through which members interact.
Shift any one of these conditions, and the patterns of the system shift.
- Broaden the container to include new partners, and new dynamics emerge.
- Introduce more (or less) difference, and energy shifts.
- Increase the richness of exchanges, and coherence may strengthen.
The CDE Model doesn’t tell us what patterns will emerge. But it gives us a way to understand the conditions that make certain patterns more likely than others
Why CDE Matters
The CDE Model helps us move from trying to control systems to influencing them more artfully. It reminds us that:
- We cannot force a system into a predetermined state.
- We can shape conditions so that life-giving patterns are more likely to emerge.
- Small shifts in containers, differences, or exchanges can create significant ripple effects.
In HSD, this is what we mean by “creating conditions for generative change.” We don’t control outcomes; we influence possibilities.
Using CDE with Adaptive Action and Pattern Spotting
The CDE Model is especially powerful when combined with Adaptive Action and Pattern Spotting.
- Adaptive Action gives us a rhythm for testing and adjusting: What? So what? Now what?
- Pattern Spotting trains our attention to notice shifts and signals in the system.
- CDE gives us a framework to interpret what we’re seeing — and to choose which conditions we might influence.
Together, these approaches help us see and act in complexity with more coherence and creativity.
Why This Matters for Working with Networks
The CDE Model provides a simple but profound lens for working with CAS. By paying attention to containers, differences, and exchanges, we can:
- Recognize the conditions shaping current patterns.
- See how small shifts might create openings for change.
- Work with complexity without falling back into force or control.
- Design interventions that seed coherence and possibility.
In short, the CDE Model offers us a way to influence the deep dynamics of systems — not by imposing solutions, but by shaping the conditions for life-giving patterns to emerge.
This concludes the 8-week series for the 2025 RE-AMP Systems Thinking Academy. Thank you for following along. I’ll be continuing to share reflections, tools, and practices for systems thinking and mapping in the months to come.