Brainwriting is a technique very similar to Brainstorming, with the difference that it is done on paper. The idea is the same as in this technique: a group of people is brought together in a common space in which a problem is proposed that the participants must solve together.
In order to solve the problem, each participant must give their opinion based on ideas that they will write on small papers (or on a single piece of paper, in a list) in such a way that they solve the problem posed. The technique can be helpful if group members have difficulty speaking in public.
To begin, the group members are given time to write down all the ideas that come to mind on a blank piece of paper (it is not necessary to leave a lot of time, or have to come up with many ideas about it). When the given period has elapsed and under the indication of the mediator, the team members will change roles with the ideas noted down, either mixing them up or passing them on to their companions next door.
The ideas will be read by the person whose turn it is, and new ideas should be written that are related or not to those that this participant had. After repeating the process a few times, all the ideas that have emerged will be read aloud and the mediator will highlight (underlining, circling or writing down on a board) those that he and the group consider most relevant.
The mediator must be an impartial person regarding the issue to be discussed, as well as knowing it very well. You must avoid conflicts and try to resolve doubts among the attendees.
Finally, it should be noted that this technique can be done via email if necessary -for example in the companies- which makes it easier for the group not to attend the room for any reason not necessarily a problem.