Your organization has decided that the Oracle Application Development Framework (ADF) might be the right tool to build your next enterprise application—now you need to set up an experiment to prove that your assumption is correct.
You can compare the situation at the start of a project to standing in front of a mountain with the task to excavate a tunnel. The mountainsides are almost vertical, and there is no way for you to climb the mountain to figure out how wide it is. You can take either of the two approaches:
You can start blasting and drilling in the full width of the tunnel you need
You can start drilling a very small pilot tunnel all through the mountain and then expand it to full width later
It's probably more efficient to build in the full width of the tunnel straight from the beginning; however, this approach has some serious disadvantages, as well. You don't know how wide the mountain is, so you can't tell how long it will take to build the tunnel. In addition, you don't know what kind of surprises might lurk in the mountain—porous rocks, aquifers, or any number of other obstacles to your tunnel building.
That's why you should build the pilot tunnel first—so you know the size of the task and have an idea of the obstacles you might meet on the way.
The Proof of Concept is that pilot tunnel.