Currently, the aerodynamic effects produced in flapping flight are not understood completely. Even though, there are methods to compute the forces acting on three dimensional wings or two dimensional airfoils such as direct numerical simulations, they are to expensive in computational time and fail to give any insight into the actual mechanics of the problem. In classical (fixed wing) aerodynamics, it is typical to separate the problem into the angle of attack, the camber and the thickness problem. In this way the effect of each design variable for an airfoil is known and design for specific performance is simpler. In flapping flight, decomposition of the contributions to the force has been implemented in two dimensions, most recently by Martín-Alcántara in [8], by using the algorithm created by Chang in [2]. However, it is known that two dimensional flow does not produce equivalent results to three dimensional flow. Moreover, actual designs of flapping vehicles will need to take three dimensional effects into account to yield a high performance. In this paper, a tool to compute the force decomposition described by Chang [2] is developed. This methodology requires the calculation of a surface potential. So the library BEMLIB [10], was modified to solve the potential flow in two and three dimensions over wings and airfoils. The library was validated against analytical results in the two dimensional case and known numerical results in three dimensions. For validation purposes, the decomposition algorithm was applied to a wing describing sinusoidal heaving motion. The results of this decomposition are presented and the limitation and requirements of the decomposition algorithm discussed. Ingeniería Aeroespacial