By definition, innovation creates something new.
Therefore, if we think of innovation as a project, it's not very well defined, if at all. Innovation projects best lends itself to an "adaptive" project lifecycle, which is highly responsive to the changing needs of the project. It's also known as the "agile" or "change-driven" approach. It's also incremental and iterative approach, but the iterations are very rapid. Early iterations may focus more on planning activities than later iterations. This is covered in detail by the Project Management Body of Knowledge.
Here's how the process works. A larger project is broken down into a set of subtasks that can be completed within 2-4 weeks. Each iteration set is assigned a fixed duration and cost and a defined set of deliverables, or desired outcomes that can be accomplished with 2-4 weeks. And by "accomplished", we mean ready for review by the customer. The backlog is added to and revised on a continual basis.
This approach requires intensive project management and participation by the customer. But the tradeoff is project agility and quick iterations, especially when the project scope is not well defined.