FORTUNE — Dear Annie: I’m a member of a 14-person brand-management team for a product whose sales were skyrocketing for a while but have now leveled off. My boss told me that senior management is “concerned” about this plateau where we seem to be stuck, and he wants me to organize some brainstorming sessions to try to come up with “outside the box” ideas for increasing sales.
Not only have I never done this before, but it’s stressing me out for two other reasons. First, previous brainstorming efforts have led nowhere, so people here are pretty jaded about the whole idea. And second, my boss gave me the impression that this assignment is kind of an audition for a promotion, so I don’t want to screw it up. Do you or your readers have any suggestions? —Pittsburgh Pat
Dear Pat: Funny you should ask. I’ve just been reading a fascinating new book about creativity, Thinking In New Boxes: A New Paradigm for Business Creativity. Of course, an entire mini-industry has sprung up to teach people how to think more creatively at work, and, you may have noticed, there’s been no shortage of books about innovation.
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This one is a bit different. Co-authors Luc de Brabandere and Alan Iny, longtime Boston Consulting Group creativity advisors, base their five–step method on what has worked for thousands of real-life managers they’ve coached — starting with a persuasive analysis of why most brainstorming is a waste of time.
“In most brainstorming sessions, people are told to think up something new, while the old assumptions and preconceptions that created the problem in the first place are left unchallenged,” says de Brabandere. “So if you get people together and just let them loose on a problem, without questioning their assumptions, they will often be drawn right back into the same old rut.”
Take, for instance, your sales slump. Before you start asking people for ideas about how to boost sales, de Brabandere and Iny suggest you take a step back and examine the situation more broadly. To think outside the box, you first have to see the box. “Are sales approaches really the issue? Maybe the market has moved on, or maybe it’s saturated,” Iny says. “Maybe the competition has changed the game. Maybe you aren’t even in the right business anymore.”
One example of how a fresh look at these basic questions can open up a whole new (and way bigger) box: Back in the 1970s, BIC Corp. Was looking for ways to sell more plastic pens, “until executives stepped back and asked themselves what business they were really in,” says de Brabandere. “They realized their business was bigger than just pens, it was disposable plastic items” — a realization that soon had BIC growing like mad by selling lighters, razors, and other products.
Or consider a current case: Mark Zuckerberg’s campaign to bring the whole world online. Thinking inside the same old familiar box would prompt the question, “How can we wring more cash out of current Internet users?” Instead, or in addition, Zuck is turning his focus to the 4.7 billion people on the planet who aren’t wired yet.
Besides neglecting to think beyond old assumptions, the authors say the second-biggest reason so many brainstorming sessions fizzle out is a lack of structure. Thinking In New Boxes is packed with specific tips for focusing people’s attention so they won’t “veer off in random directions,” as Iny puts it.
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One of these, he says, is to ask the group to imagine how “the most unreal, unexpected, seemingly impossible events” could affect the business — an exercise that tends to crush complacency. If brainstormers at Blockbuster had tried this, the authors note, they might have foreseen that the Internet, especially Netflix (NFLX), could end up eating their lunch, and lessened their reliance on retail stores much sooner instead of scrambling to play catch-up.
As for how to get your jaded colleagues on board, Iny and de Brabandere have found that it’s often a simple matter of not rushing them. “Participants tend to begin the [brainstorming] process with their backs up,” they write, since “everyone has been through workshops or brainstorms that don’t work.” With enough time, however, “they let their guards down. They free up.” How much time is enough? “When in doubt, give yourself at least half a day (or a full day if resources permit) in order to dig as deeply into the creative process as possible.” Good luck.
Talkback: Have you ever participated in a brainstorming meeting that produced valuable ideas? What made it work? Leave a comment below.