Rob Bridgett has posted a great feature on how to integrate audio production into your game development schedule:
This feature takes a brief look at how to tie audio production dates into the overall delivery schedule of a large-scale video game — including the key dependencies you should be fully aware of.
During production, it is often the case for each component of game audio to be either dependent on some other area of work to be completed, or some other area of the game is dependent on audio finishing a particular piece of work. Understanding how all these pieces are inter dependant is the key to not only locking-in and delivering on-time, but also to staying agile and having a production schedule that is simple to read and aides communication across groups.
The working practice behind scheduling for video game production is an increasingly complicated one and boils down to an approach that embraces locking-in tightly and firmly committing, yet being ready and prepared for changes at any time.
At the same time, you must also fully understand that any changes will have implications elsewhere in the production.
Be sure to check out the full feature on game audio over at Gamasutra.