Innovation as a rearrangement of ideas

Here's a half-baked idea on innovation. Innovation is rearrangement of existing ideas into a new form. I think that logically the definition can be shown to be robust. The rate of innovation can be written as I=I(labour, available ideas, factors influencing the rearrangement). The representation has the advantage of making innovation a mundane outcome of other inputs, which allows it to be made an endogenous variable in a model easily.

The idea may stay half-baked, or it may be cooked with a cherry and candles some day.