Traditionally, the assessment of whether a claimed invention achieves an inventive step over the prior art is handled somewhat differently in the European and the German patent system. In particular, the European Patent Office and its Boards of Appeal follow the problem-solution-approach. In contrast, the German Federal Court of Justice (BGH) does not apply the problem-solution approach, but takes a more holistic approach. Accordingly, attacking a claimed invention for a lack of inventive step requires different considerations in European opposition proceedings on the one hand, and German opposition or nullity proceedings on the other hand.

So far, a first important step in the problem-solution-approach is identifying the closest prior art as a starting point. According to established European case law, in selecting the closest prior art, a central consideration is that it must be directed to the same purpose or effect as the claimed invention, otherwise it cannot lead the skilled person in an obvious way to the invention. While it is possible that several suitable starting points exist – and even possible that a piece of prior art relating to a similar purpose is considered a suitable starting point in the presence of a piece of prior art relating to the same purpose (T 1841/11) – it is nevertheless also possible that an inventive step attack is rejected, because a piece of prior art is not considered to be a realistic starting point.

In Germany, the Federal Court of Justice (BGH) stated repeatedly that, whether a skilled person would start from a certain piece of prior art, does not depend on this piece of prior art being the closest prior art to the claimed invention. In fact, the BGH finds that classifying a piece of prior art as the closest prior art is neither sufficient (“Olanzapin”) nor necessary (“Fischbissanzeiger” and “Gestricktes Schuhoberteil”). Reason for this is that the BGH considers the selection of the closest prior art to be only possible ex post facto, i.e., with knowledge of the invention.

A recent decision (T 0855/15) of the Boards of Appeal of the European Patent Office now comes to a similar conclusion. Firstly, the Board concludes in its decision that the remoteness of a piece of prior art from the claimed invention does not, in itself, rule out an assessment of inventive step. In fact, the Board argues that if a piece of prior art is too remote from the invention, it should be easy to demonstrate that the skilled person would not have obviously reached the invention from that piece of prior art (this follows the decision T 1742/12).

However, the Board goes even one step further in its decision. According to the Board, it is necessary to assess whether a claimed invention would be obvious to the skilled person having regard to the entire state of the art. For this assessment, one or more pieces of prior art may be selected for consideration. However, no argument is required as to whether (and accordingly as to why) the skilled person would select a particular piece of prior art as starting point. In fact, the Board finds that a consideration of what the skilled person would do, in particular whether the skilled person would select a certain piece of prior art to reach the claimed invention, would amount to hindsight reasoning. This is due to the fact that the skilled person would have to be assumed to know the invention before an argument could be made as to what he would do in order to arrive at the invention or not.

This conclusion of the Board, that the selection of the closest prior can only be made with hindsight knowledge of the invention, is strikingly similar to the standing case law of the BGH.

Practical Impact:

An inventive step attack in European opposition proceedings usually requires arguments concerning the suitability of a particular piece of prior art as closest prior art – or at least as a suitable starting point for the problem-solution-approach. These arguments may become less critical, if this latest Board of Appeal decision indicates a general shift away from the importance of the closest prior art selection. Thus, the attacker may be freer in selecting pieces of prior art, from which to argue that the skilled person would have reached the invention in an obvious manner.