The success or failure in achieving the goal is an important but short moment at the end of the story. So how is interest maintained over the course of the story? By the progress of the quest toward the goal. This progress is measured by how many of the requirements have been met and how many remain.
Requirements can be logistic, such as needing to obtain five lost rubies that fit in the idol and unlock the door to the treasure. Or, they can be passionate, such as needing to perform enough selfless acts to win the heart of the princess.
The important thing is that the requirements are clear enough to be easily understood and measurable enough to be "marked off the list" as the story progresses.
In this step, list the requirements that need to be met in order for the story's overall goal to be achieved.