Yesterday, watching a bee that had snuck in my office window trying to get out, I was reminded of a simple fact that to my mind is a great metaphor.
Put a few bees in a bottle, and point the bottom towards a light source, and the bees will all belt themselves against the bottle bottom, never finding the open end. Flies by contrast buzz around at random, and eventually will, by luck, find their way out the open end.
Running a portfolio of R&D projects is a bit like having a lineup of bottles full of bees.
For some bottles you need to have light very focussed at one point, in order to concentrate the effort at that point, others you need a wider light source to enable a wider scope of activity, and others, you need light all around, with one small exit, so that eventually the disciplined bees will find the opening, and escape.
If all you have in the bottles are flies, exercising discipline is a pointless exercise, as flies just buzz at random irrespective of external motivation. You need bees, and multiple potential light sources.
Getting the right mix of disciplined process and the connection of the apparently random dots that make the “wow” moment is the core task of those running a portfolio of projects.