Additive and multiplicative complexity

B. Meyer makes an interesting point (among many from his book Agile! - The Good, the Hype, and the Ugly) about the different types of complexities in software projects. He compares the two types to pasta:

Additive complexity is like lasagne. You just keep piling new parts on top of the existing parts and it works (this is, of course, an ideal for agile projects).
Multiplicative complexity, however, is more like linguine (or spaghetti), meaning the parts are entangled and hard to separate. Projects which have lots of this types of complexities (which is more than one might think) require some upfront planning to reduce waste (which would be the result of treating these tasks in pure agile manner).