One problem with brainstorming is that it forces the process of creating new ideas. “Here we are, it’s 9:30 AM, so get wild!” Few minds do breakthrough somersaults on demand (See my post of Feb. 20, 2007: sleep on it to make a good decision.).
Reverse brainstorming takes a different approach. Meet to lay out the problem and then urge people to think about the problem and possible solutions during the days until the next meeting. If any ideas come to them, they should write them down. At the next session, the members bring together those thoughts and consider them.
In summary, Rotman Mag., Winter 2009 at 71, explains that “reverse brainstorming, then, is a meeting to collect brainstorming ideas, rather than create them” (See my post of Dec. 31, 2008: brainstorming with 5 references; Jan. 4, 2009: electronic brainstorming with decision support software; April 6, 2009: brain-writing 6-3-5; and April 27, 2009: eleven suggestions for how to brainstorm.).