Engaging the right people and departments for your innovation is crucial for your success. Not only they will provide useful and often unexpected feedback, but sooner or later you need to co-operate with them on your new idea and perhaps they become part of your project team. Of course you need a clear description of your idea first, but after that the sooner you involve all stakeholders the better your idea will develop into a concrete product or service. It speaks for itself that an impact assessment is a very crucial step to build a trust-worthy business case.
We experience that time invested in this process will pay off in the rest of your product development.