A diagram of a further decomposition of ingredients would look like this:
At the moment, a diagram of the further decomposition of equipment would look like this:
The ‘Equipment’ part is not properly broken down (or decomposed). Therefore, if the solution - or algorithm – were created from this, baking the cake would run into problems. The algorithm would say what equipment is needed, but not how to use it, so a person could end up trying to use a knife to measure out the flour and a whisk to cut a lump of butter, for example. This would be wrong and would, of course, not work.
Ideally, then, ‘Equipment’ should be decomposed further, to state which equipment is needed and which ingredients each item is used with.
The problem occurred here because the problem of which equipment to use and which ingredients to use it with hadn’t been fully decomposed.