Well it's not quite as simple as playing loads of tournies = better rank - he did actually do really well in several of the slams/masters events last year. Although interestingly he went straight out (after byes) of Indian Wells and Miami last year (vs Blake and vs Monfils), so the signs are good.
Nice thread I found where a guy is doing running calculations of Andy's ranking. I (and Arka and maybe others) would normally do this, but I'm just gonna sit back and relax since someone's has written it all out for us! Activeboard thread
Andy's already up 4 to 40 as things stand. It takes into account the Sunrise Challenger too which is cool.