The EPO's Appeal Boards early on adopted a "problem and solution" approach to obviousness. As this has evolved over the years it has required an analysis to determine what is the single closest piece of prior art and then posed the question of whether an inventive step was required to go from that closest piece of art to the invention as claimed. There has been continuing criticism of the rigid application of this approach over the years which recently resulted in an appeal board decision in the case of Aluminum alloys/Alcan acknowledging that in certain circumstances other approaches might be more appropriate, particularly in cases where the prior art contained several different proposed solutions to the same problem as that solved by the applicant or where an invention breaks entirely new ground. In its decision, the board noted that since the problem and solution approach relies on a search made after the invention is known it is inherently based on hindsight and thus can lead to the wrong result in some cases. In the case before it the board was confronted with a number of different pieces of prior art that seemed of equal relevance disclosing other attempts to solve the same problem. The board concluded that in this case the relevant test was simply whether or not any of these pieces of art "contained any pointer" to the claimed step.

Nevertheless, the problem and solution approach is now sufficiently well established that it is likely to remain the standard test for inventivity in most cases.