A major disadvantage of NGT is that the method lacks flexibility by being able to deal with only one problem at a time. Also, there must be a certain amount of conformity on the part of the members involved in NGT. Everyone must feel comfortable with the amount of structure involved. Another disadvantage is the amount of time needed to prepare for the activity. There is no spontaneity involved with this method. Facilities must be arranged and carefully planned. Opinions may not converge in the voting process, cross-fertilization of ideas may be constrained, and the process may appear to be too mechanical.