I've received feedback from my case partners that I take too long to walk through my structure. He says that "it is good but takes too much time". I tend to say what I'll look at, followed by why I'll look at it. For example, for market entry, I would say "I'd like to look at the market first, and determine the size and growth rates of this market. This would help me determine if it makes sense to enter the market in the first place. Next, ..."
How should I walk the interviewer through my structure? Note that I take less than 20s to come up with a structure (I come up with the main points) and I write the subpoints (size, growth rates, etc) as I walk the interviewer through it.