Remember that on TV and in the movies, zombies are people who are undead - not really living, and not really dead. They seem to resort to cannibalism and pursue the living. Most zombies move lethargically and don't really threaten the living until there are a large number of zombies crowding our heroes, which is when the fun begins. Everyday objects like chain saws or electric guitars become the equivalent of light sabers in zombie movies.
But in real life, especially in your innovation efforts you face dangerous zombies that threaten good ideas and good intentions, and crowd out your best ideas. These zombies are the "undead" ideas - ideas that didn't get approved or funded, and no one bothered to kill. By my estimate most firms have hundreds of these undead ideas laying around, just waiting for the right opportunity to spring up into that quasi-undead status.
When executives say "we have plenty of ideas" they are usually referring to these zombie ideas, only they don't recognize them as zombies. Since they are still "on the books" or in the pipeline, executives assume the ideas are still viable, when the rest of us know they are zombies at best that should have been killed outright long ago. These zombie ideas crowd out good ideas, distract the teams and enthrall the executives, so that innovation becomes much more difficult.
What's needed in most firms is a good zombie killer - perhaps like the role Woody Harrelson played in Zombieland. Using a wide array of instruments he killed more zombies in more ways than the plague in London. What you need is to find your Woody Harrelson, the person who can make decisions and actually kill all the zombie ideas that are clogging up your innovation pipeline. By conservative estimate 75% of most innovation pipelines are ideas that have been killed previously or should have been killed, and these ideas continue to attract attention and investment. And with what appears to be a relatively robust pipeline, why generate or work on more, new ideas?
Whether your firm is just getting started in innovation or has had an innovation effort for a long time, one good way to start your work is to first kill all the zombies. Then you'll have a real sense of the breadth and depth of your innovation portfolio and you'll know where to start. By killing all of these useless ideas you open up opportunity and oxygen for new thinking and new ideas.