the "big ball of mud" that gets wrapped around factoring-1 IS the re-use. its not like a team writes one component, then says "OK we're done!" and writes the next. you write your infrastructure hand-in-hand with the code that uses it. but as you understand your infrastructure problems, you don't fix them, because "we'll just write a few more things around it for this milestone". for the next five milestones. software human process doesn't happen in nice, discrete chunks which are easy to understand, talk about, and justify.