A system is a set of interconnected parts, with relationships, that are organized within well-defined boundaries, that form a whole and work together to achieve something. 

For example, if we were to take the constituent parts of a laptop - the circuits, wiring, screws, glass - they are pretty valueless as a pile of parts. But connect them in one functioning system, they create a powerful computer - a valuable and practical device. 

In terms of systems thinking, we can tell the story of the blind men and the elephant, which is representative of how different departments within a business are often siloed. In the story, the blind men are each touching different parts of the elephant: the one touching the trunk wonders if it's a snake; another touching the leg thinks it's a tree; another touching a tusk thinks it is perhaps a weapon, and so on. But when the silos are removed and all of the blind men work together, or different departments within the business work together, they can see that it's actually part of a greater whole – which in this case would be the elephant. 

In business organizations, it can be easy to lose sight of systems thinking - to not recognise that when parts of a business process are not acting sustainably, then there are implications for the whole system. When one part of an organization or supply chain is sinking or dysfunctional, the whole supply chain organization will eventually sink as well because they are interconnected.

Systems thinking is not about the individual, but rather part of something bigger. It's an intentional process – think cause and effect. Everything is interconnected – seeing the whole and recognizing the patterns. Systems thinking is the mental discipline that enables sustainability practice.

A really great definition of systems thinking from Senge and Lannon-Kim is as follows: “Systems thinking is a discipline for seeing wholes, recognizing patterns and interrelationships, and learning how to structure those interrelationships in more effective, efficient ways.”

When we view a system as a whole, we can take stock and flow information, enrich it with environmental and social impact data, and generate a value map. 

For example, a value map for a pair of jeans might start with stock points - places where materials and products are held - and add to this the connecting lines of product flow and processes - shown here with arrows. We can then add on relevant stakeholders involved in the process, and finally, identify the environmental or social impacts of each stage. 

When we consider that over a billion pairs of jeans are sold each year, involving 2.7 billion meters of fabric, you will appreciate the significance of systems thinking for evaluating social and environmental impacts. 

This way of thinking allows us to look at the system holistically, to leverage interrelationships within a system, and to intentionally move toward sustainable practice.