Prerequisites are events that must happen in order for the Requirements to happen. They are an added layer of challenges to your plot outline. Like Requirements, as Prerequisites are met, the reader feels progress is being made towards the goal. For instance, in order to free the Princess, the hero must recovery the key from its hiding place, but first (Prerequisite) he must defeat the dragon guarding it. In order to win the maiden’s hand, the gallant suitor must show he would not risk losing her for anything. But before he has a chance to do that, he must show he is willing to risk everything to win her (Shakespeare’s The Merchant of Venice).
If the Requirement for our novel about the executive is that she must go out on several dates, perhaps the Prerequisite is that she must sign up at a dating service, buy a new wardrobe, or get a make-over.
Take a look at your chosen Requirement and make a list of possible Prerequisites that must be accomplished before the requirement can be met. Choose one.