Myth of the Silver Bullet Game Production Process
There is no one development process that fits all; Scrum, Prince, Lean, Extreme and whatever the current fashion is all have their place and can work but it’s typically a hybrid that works best for you now. Things will change over time and the next team, platform, role or project may require an entirely different approach. Having an adaptable approach will make things smoother for you.
Consider more formal methods for the meta-project such as milestone structure and operate an agile process within those. Consider “beach head” style changes to your production pipeline by introducing the new process to aspects of your project, e.g., introduce Scrum on your AI team before you unleash it.
This way, you’ll get to iron out the bugs and if things go well then at least you’ll have trusted people on board when it comes to making the broader change.
Consider running agile process for the highly creative periods such as pre-production and concept and more formal methods for the middle bit where you’re largely implementing your design.
Whatever it is, think about the implications on the production and people involved as they’re both intrinsically linked.