My favorite example involved a group of thirty boys, ages ten and eleven. They were asked what they thought of receiving $5 a week just for going to school. Not surprisingly, the boys loved the idea. Then de Bono had them do a PMI on the idea.
Amazingly, by the end of the three minutes, twenty-nine of the thirty boys disliked the idea and for a multitude of unusually mature reasons: other prices, such as the cost of meals, would increase; teachers would have to be paid less; and parents might react by withholding presents or pocket money. Oh yes, and the bigger boys at school might beat them up and steal their money. The boys might never have considered these ideas without participating in this exercise.
Importantly, as de Bono notes, the boys achieved this change in mindset on their own with no outside intervention or influence. And that's been my experience as well in running this exercise in organizations.
One minute per round may seem like too little time, but the very brevity of the exercise is one of its strongest features. People's attention becomes riveted on carrying out the exercise and one minute allows just enough time to jot down responses without analyzing or judging them. For that reason, it's important to adhere to the one-minute per round time limit, rather than soliciting people's views about the plus and minuses and discussing each one in turn.
In debriefing the PMI with the IT/customer group, I had teams report on their pluses, then their minuses, and finally their interesting points, and as they did, I recorded them on a flip chart. Strikingly, it was the customers who reported some of the positives: "We'll save time because we'll know the steps we need to take." And the IT personnel reported some of the negatives: "Some standards are overly complex relative to the customer's need."
In fact, at several points, customers seemed eager to explain to their co-workers on other teams why they felt strongly about their pluses. And some of the IT staff now defended some of the minuses they might not have even considered before.
One of the important "ah-ha's" in this exercise is that an idea can be positive for some people and negative for others. For example, although two groups listed that standards create boundaries, one group listed it as a positive, and the other as a negative. Both perspectives are valid, and the very fact of its being seen as a positive by some and a negative by others provided food for thought regarding how standards can help—or hinder.
With customers acknowledging pluses they hadn't previously considered and IT staff now recognizing that certain standards could overly constrain their customers, the stage was set for them to jointly consider standards from a more open-minded perspective.
Be on the lookout for situations in which you, your team, your department, your customers, or other groups you interact with have taken a stand strongly favoring or opposing a particular idea or approach. A PMI might be just the exercise to help shed light on alternatives. Best of all, no one can claim they don't have the time.