When my factory has grown so big and unwieldy that I start to feel a massive refactoring is in order but that it's going to be too much work, I just start a new

When my factory has grown so big and unwieldy that I start to feel a massive refactoring is in order but that it's going to be too much work, I just start a new game and use the lessons I learned from the previous game to design a better factory next time.