The Planning Cell method - developed by the German professor for sociology Peter C. Dienel - engages approximately twenty-five randomly selected people, who work as public consultants for a limited period of time (e.g. one week), in order to present solutions for a given planning or policy problem. The cell is accompanied by two process-escorts, who are responsible for the information schedule and the moderation of the plenary sessions. A project may involve a larger or smaller number of planning cells. In each cell participants acquire and exchange information about the problem, explore and discuss possible solutions and evaluate these in terms of desirable and undesirable consequences. Experts, stakeholders and interest groups have the opportunity to present their positions to the cell members. The final results of the cells' work are summarised as a 'citizen report', which is delivered to the authorities as well as to the participants themselves.
The Planning Cells work best in a situation in which an urgent problem has to be resolved in a short period of time and when different options, each posing different benefits and risks, are available. The process works optimally when the issue is not too controversial and has not already polarised the attitudes of the affected population. However, Planning Cells can address even highly controversial issues if the majority of participants are selected by random process. This random selection of citizens increases the acceptance of the results as they are representative of the relevant population.
The results of the planning cell are completely open. In contrast to some other participatory methods, there are no pre-defined solutions. The citizen advisors develop their own solutions and recommendations based upon their experience in the planning cell process. The recommendations of the citizen advisors tend to clearly promote action in, and protect the interests of, the general community. Citizens do not try to push through their own individual interests but seek the well-being of the community as they understand it.
Planning cells are processes of political education. As a side effect, the participants learn about various institutions, processes, pressures and constraints involved in political decision-making. Planning Cells could be reconvened several times or different panels could be organised for the same subject over a longer period of time.
Planning Cells are not well suited for issues that pose major inequities between different regions or social groups. In these cases, randomly selected citizens are not perceived as legitimate negotiators for the groups that face these inequities. In addition, decisions involving only a yes-no alternative are inappropriate for Planning Cells because participants tend to select the 'easy' solution of objecting to any new development, especially if the affected community does not equally share the benefits.