Disclosed is a method for automatically establishing a system of equations according to the finite element process. Said system of equations relates to nodes of a structure comprising a body and an adjacent layer (K1). Finite elements are created for the body. The layer (K1) is automatically subdivided into volume elements by using geometrical data about the layer as well as specifications for meshing the layer. A finite element (110.2) of the body and one closest point (205.1) on said finite element are determined for at least one node (201.1) that is part of a volume element of the layer, said finite element (110.2) being located closest to said node. A function is created for a physical relationship between the value that the physical variable takes at the closest point (205.1) and the values which said variable takes at the nodes of the closest finite element (100.2). The value of the physical variable at the determined point is eliminated by using the function when the system of equations is established. The invention allows the number of unknowns to be reduced in the system of equations.
