Complexity becomes manageable when relationships between parts are understood.

Sheer number of parts is not what makes something unmanageable. It is not knowing how they connect, which change affects what, and where the dependencies run. Once the relationships are understood, a large system becomes navigable, and once they are not, even a small one becomes frightening. Understanding the structure is what converts complexity into something workable.

When facing something complicated, spend your first effort on the connections rather than the components. Draw them if you can. The map is usually more valuable than the inventory.