architecture

The same components, stacked so each layer rests on the one under it. A layer may call the layer below and may not reach past it. That rule is what makes the drawing useful. An arrow that skips a layer is either a shortcut you did not know you were relying on, or the reason a change in one place keeps breaking something two levels away.

The same components, stacked so each layer rests on the one under it. A layer may call the layer below and may not reach past it. That rule is what makes the drawing useful. An arrow that skips a layer is either a shortcut you did not know you were relying on, or the reason a change in one place keeps breaking something two levels away.

Example

Best when the parts have a clear order of dependence and you want to see what a change at one level touches.