For example, let's say our idea is about incremental innovation on an existing product. Sometimes these ideas will get killed because someone is worried about cannibalizing the existing product or product line. Or let's say our idea is about attacking another firm's bread and butter product. These ideas will get killed because we don't think we have the capability or technology. Or possibly the ideas will be about an interesting, radical new approach or process. That's when the Not Invented Here syndrome sets in.
So, for every reasonable category of ideas, it is easy, almost too easy, to create very rational reasons why we should not pursue the ideas. In fact, one could argue that the conventional wisdom should suggest that every idea should be eliminated very early in the crib. The only problem is a firm with no new initiatives, no new ideas will simply stagnate and die.
So, there's got to be a force or group that works to find the good in ideas. Instead of immediately eliminating ideas that might cannibalize a product, we might want to evaluate whether or not our competitors will attempt to attack that market, and by cannibalizing our products we can sustain or grow market share. It could be that the time is right for radical innovation, and if we don't do it, someone else will.
Most people prefer the devil's advocate position, so ideas face an uphill climb from the get-go. Who within your firm is responsible to argue for the defendent? Who's the advocate for the idea that starts life on death row?