I have my own answer to this but I'm curious as to how other people see/handle it.
Projects, by our definition, consist of multiple steps. And in many cases those steps are linear - you have to do things in a specific order to get the project completed. This makes working out your next action fairly simple.
But what about those cases where the steps aren't necessarily linear - where you could do any of a number of them at any or even the same time? As an example, you may be thinking of adding a new product line to your business, but you have several possibilities. You need to research each of the possible products and then make a decision. There's no reason that you couldn't be doing any or all of the research actions simultaneously.
How do people handle the NA part of this situation?