This, you mean:
We implemented milestones.
We are no longer working on the whole game at once. We focus on small milestones that are major accomplishments in and of themselves, before moving onto the next milestone. This has included a change in development where multiple level designers, modelers, and texture artists will tackle a chapter together to push it forward to completion on a much smaller timescale than in the past. In actuality this has been a huge boon our development, and I've never been more proud of our developers for banding together to get shit done when it needs to be, as much as in recent months.