The best way to cut your time down is to repeat the process time and time again, and refine it each time, trying to be as efficient as possible. That is, if time is an issue for that brewday. Me, while I like being efficient and managing my time well, there are some brewdays where I prefer to just soak it all in and relax. In that case, a medium-gravity AG brew will take maybe 4.5 hours. However, other days I am more worried about time, so I use every second wisely. If it's an ale that isn't made with pilsner malt, and it's a relatively medium to low OG (meaning only 60 minute boil), and I'm not doing a decoction or a stepped mash, and I'm being very efficient, then I can go from the first grain bag being opened up, to cleaned up well enough that you couldn't even tell I brewed, in 3.75 hrs. But it's rushed, that way.
A few tips...first off, get some fermcap/defoamer to help prevent boilovers, make sure your kettle is big enough to handle slight boilup, and most importantly, get a fan that has an adjustable up/down axis, and train the fan on the surface of the boiling wort. This will prevent boilovers and increase evap rate. All of these things allow you to do other things while the wort is boiling, and not have to sit there worrying about boilovers. What you need to do is use the down time during the mash and the boil to do other things. Heat up your sparge water, measure your hops, clean up equipment that you don't need to use anymore, sanitize your fermentation vessel. In essence, think ahead and don't sit around twiddling your thumbs. But still, just know that no matter how efficient you are, you're not gonna get down to extract batch time. The simple fact that you have to add about an hour and a half for heating up strike water, mashing, and sparging, means that it's going to take longer regardless.