Systems thinking is holistic and considers the manner in which a system's components are connected and interdependent. It also considers the ways that a system evolves over time and its relationship to smaller and larger systems. It is a particularly useful means of understanding and formulating approaches to complex problems.

To illustrate the difference between simple, complicated, and complex problems, opening a tin can is simple, provided you have a can opener. Building an aircraft is complicated - involving many different parts, processes and subsystems. However complicated, doing it once means that you can do it again following the same blueprint. But raising a child is complex – doing it once successfully is not an assurance that it will be as easy the next time, as there are so many variables and changing contexts to consider.

Problems like climate change, chronic disease prevention, or homelessness are complex. They do not exist in isolation, but are interrelated with other problems. And yet, according to complexity theory, sometimes small changes in systems can produce big results. 

Thus, a common support for systems thinking is systems mapping. Put your problem on a page and ask – what problems are contiguous to this problem? What are its component parts and what relationships can be observed among them? What self-reinforcing patterns do you notice? Where are there blocks or bottlenecks? Do you see places where interventions might trigger a tipping point? 

Here is an example that illustrates this approach applied to the problem of how to grow the field of impacting investment.