Milestones
Commercial game development projects may be required to meet milestones set by publisher. Milestones mark major events during game development and are used to track game's progress. Such milestones may be, for example, first playable, alpha, or beta game versions. Project milestones depend on the developer schedules.
There is no industry standard for defining milestones, and such vary depending on publisher, year, or project. Some common milestones for two-year development cycle are as follows:
Read more about this topic: Computer And Video Game Development, Development Process