Personally I prefer allowing devs to submit proposals for projects, basically innovation time but they say upfront what they're going to be doing and if approve

Personally I prefer allowing devs to submit proposals for projects, basically innovation time but they say upfront what they're going to be doing and if approved it becomes a project that is managed the same way as ordinary work but the client is the company itself. In my experience devs have proposed (and eventually built/ongoing) a new data API, a mobile app, a huge refactoring, framework upversioning, a massive dependency reduction, a geographic dashboard for our datasets, an optimisation engine and a prediction engine. Probably added more value than any other scheme I've seen.