It uses the insight that we grasp our environment by assigning things that are similar to the same category.
Example: An airplane resembles a helicopter. Both resemble a bird (at least more than a rabbit). As a result, there is a risk that we will always remain in the old and familiar pattern of thinking, even when developing new ideas. To come up with new ideas, these obvious categories have to be broken through and the perspective changed.
This opens up new possibilities in problem solving and idea generation. The constraint analogy makes this possible in a quick way and usually works very well even with inexperienced teams.
In contrast to the classic analogy method, analogies are deliberately sought here that are different from the product or service. These are set as stimuli for new ways of thinking. Basically, the principle of the forced analogy is similar to the stimulus picture method or the stimulus word method, but the analogies in the forced analogy are usually formulated in a more descriptive way. This often makes them less abstract and somewhat easier to implement for many participants.