http://www.wired.com/wiredscience/2012/01/the-mathematics-of-lego/
This article talks about a study of comparing LEGO set as a system and its pieces as building blocks. It concludes that the larger a system is, the larger the amount of building blocks are necessary and therefore there is a grow in types of building blocks. This relationship is sub linearly though, as the system grows, fewer types of building blocks will be used and this is compared to how as a city grows, fewer gas stations exist. The point is to use the same pieces efficiently.