This document discusses build system maintenance. It notes that build systems require 12% of a developer's time on average and that build maintenance slows development. The document presents a four-dimensional study of build maintenance that examined size, evolution, coupling and people dimensions. It found that build churn was greater than source code churn. The document also discusses whether build ownership is dispersed amongst many developers or concentrated within a small team. It concludes that tool support is needed to help with build maintenance tasks.