Solving real-world problems is not done by starring into your black mirror. It is done in the real world talking and collaborating with real people. Even if your product is web-based, in most circumstances, it will serve real human beings at one point — hopefully at least.
The following two phases — Develop & Deliver — are all about «doing things right» (goal) and finding the right answer or the right way to solve the problem. That’s when we talk about executing the «experience design» (outcome).