compose

Steps

1. What does each part do on its own?

List the parts in hand and what each does by itself. A part that cannot yet run on its own is not ready to join; say what it still needs.

2. How must the parts be arranged for the whole to work?

For each pair that touches, name what passes between them or holds them together: what feeds what, what constrains what, what contains what, what comes first. Leave pairs with nothing between them unconnected.

3. What does the arrangement do that no part does?

Name the property that appears only in the assembly, stated as the purpose the parts now serve together. Where nothing appears, the parts form a list, not a whole: say so and stop.

4. Which parts does that property need?

Remove each part in turn and say whether the property survives. A part whose removal changes nothing does not belong to this whole.

5. What does the property need that no part supplies?