I read an article a couple of days ago (maybe even linked from these forums) about how the Norwegian (could have been some other Nordic country though, I dont remember exactly) conscripts who serve only for 6 months are essentially useless since there is barely any time for decent training.
I think that 1 year is probably enough to train them up, but you also want those trained soldiers to actually then apply their skills in the defense of the country. And some types of training (like large scale maneuvers, eg: Vostok 2010) arent practical to carry out all that often. If conscripts serve for 2 years rather than 1 they have a much better chance of participating in such training (more than 2x, since you arent going to send a fresh recruit to such maneuvers).
But anyway, should get back on topic.
Usually conscript training consists of following steps: - basic soldier training; - specialist training (ex.: machinegunner, paramedic, signalman, grenade launcher operator and etc.); - squad training; - platoon training; - company/ battalion and larger units training.
Those large exercises normally are part of last conscript training phase.