In a short preliminary talk before the constellation, we sort out the issue. We only need very significant information for eg. severe illnesses, early loss (father, mother, siblings, children), experience of violence, war, displacement or a bankruptcy.
After we have decided which persons (or phenomena like diseases or feelings) are important for the constellation, the client chooses intuitively representatives from the group participants and directs them to their individual position in the room. After that he or she can sit aside to watch as the facilitator of the constellation starts to work with the representatives. The aim is to find a constellation where everybody feels save and in peace.
Family constellation works beyond the limits of mind which usually tries to figure out, understand, define and keep things. Life is larger than mind. During this work, we entrust ourselves to the dynamics in the field which strives for balance like everything in nature. We are not designer of the process, rather than observers of what wants to be seen.
That is true for representatives, too. Significant is what happens in body and soul, which movements can be notices there. We can trust them. Certain prior knowledge is not needed.
Another form of Family Constellation is the covert constellation. In that, only client and facilitator know what is the issue and who is introduced to the constellation. This could support representatives to follow even freer their inner movements.
A usual constallation lasts some 60 to 90 minutes. Sometimes it could take less or more time.