The pile-up of dislocations against grain or phase boundaries in
uences the strength of metals. This effect was studied before, using idealized infinite vertical walls of edge dislocations. However, the question is if the assumption of idealized walls is not too restrictive. In this report we try to justify or falsify the wall assumption by considering more general arrangements of the edge dislocations. We will consider two different configurations. In the first configuration the dislocations are placed in a staggered way on multiple slip planes, with on every slip plane the same number of dislocations. Furthermore, we consider an arbitrarily distributed configuration. The dislocations are randomly assigned to slip planes in a certain domain and the number of dislocations on one slip plane is not evenly distributed, i.e. it is also possible to have no dislocations on a slip plane. For both situations the evolution of the dislocations configuration is calculated. In the staggered configuration the dislocations form aligned vertical walls in time. Also in the other situation, where the dislocations are
arbitrarily distributed over the slip planes, the dislocations go to a wall-like configuration. From the evolution of the dislocations it can therefore be concluded that the dislocations tend to form aligned vertical walls of dislocations. So the wall assumption is not too restrictive.