When to use it
Use it to take apart a physical item being invented.
Use it to decompose a logical problem into its constituent parts.
Use it to explore individual parts and relationships.
Use it to seek the most important focus.
How to use it
Bound the problem
Define the overall problem or item under investigation, to create a ‘closed problem set’.
For example it may be a physical machine or a task that is to be undertaken.
Break down the problem
Identify the primary boundaries of division. This may be physical or logical parts. Each of these parts will be a complete item in itself. The sum of the individual parts will add up to the original parent item.
Explore each part and its relationships
Examine each item carefully to understand it as a complete thing itself. Explore the relationships that it has with its parent item and also with the other peer items.
You can visualize the hierarchy with such as a top-down tree or a center-out spider diagram.
Build the hierarchy
Repeat the careful process of breaking down and examination of the parts and relationships such that you end up with a better understanding of the whole.
Seek the best focus
Now that you understand the whole, think about the areas in which you can best focus. Look for places to innovate, to replace, to combine and so on.
An engineer is considering the brake assembly on a car. He first looks at the whole system from many angles and watches it work. Then he takes it apart carefully, looking at how the calipers and brake disc interact, how the cylinder and piston work and fit together. In doing so, he notices how a rubber gaiter is stretched at extreme ends of piston travel. Focusing, he continues to break down parts of the gaiter: the ends, the folds and so on.
Doing some experiments, he finds that the gaiter folds split after a while. With a careful redesign of the gaiter, he makes the operation of the brake more reliable.
How it works
Many problem situations are hierarchical in nature, and will yield to breaking down into component parts. Doing this slowly and carefully allows attention to be paid to how the whole system works, and hence enable the discovery of problems and the triggering of ideas.