The book has a chapter about how to optimize variability in the product development process. The key idea is that variability is not inherently good nor bad, we just care about the economic cost of variability. There are lots of asymmetries in the payoff functions in the software context, so the area is ripe for optimization, and that means sometimes you'll want to increase variability to increase profit. But if we're mostly concerned that software development is too variable, there are lots of ways to decrease it, like pooling demand-variable roles, cross-training employees on sequentially adjacent parts of the product lifecycle, implementing single high-capacity queues, etc.