While design by inversion focuses on changing a design idea or concept, problem reversal focuses on changing how you think about the problem itself.
Consider this example. If the problem is one of stopping a leaky roof, then the reverse is to stop a leaky floor – i.e. rather than stopping the leak in the roof, vent the leak to the floor (and then just drain it). Obviously you can't just reverse one problem and solve it in a trivial way. The point of reversing a problem is to promote so called lateral thinking, which is a $50 way of saying “coming up with really new ideas.” So, reversal is more about reversing the way you think about a problem or a design, rather than reversing the design itself. Some other examples of reversal include the following.
|Problem||Initial Solution||Reversed Problem|
|You need to stop groundwater from entering a pit being dug.||Put up a barrier that forces water around the pit.||Instead of trying to stop the water, suck it forward with a vacuum system, into a pipe that you can route off-site.|
|Designing a playground so that children will tend to not walk in front of the end of the slide where then can be struck by other children coming down the slide.||Having a large open space at the end of the slide so that children can jump out of the way.||Turn the end of the slide so that children are directed immediately towards another activity with a staging area (e.g. a ladder they can climb).|