3. Closest prior art

In T 1450/16 the appellant (applicant) submitted that the skilled person would not have chosen document D1 as the closest prior art. The board did not agree with the assumption relied on by the appellant that, according to the basic problem-solution approach, the person skilled in the art may be entrusted with the task of selecting the closest prior art or a suitable starting point for the assessment of inventive step, which is the first step in the multi-stage method of that problem-solution approach. In the board's view, this would mean that the same (fictitious) person as the one who finally assesses the obviousness of a certain claimed subject-matter had already selected their "favourite" prior-art document in order to conduct that assessment. Given that the objective technical problem was to be derived from the distinguishing features established with respect to the selected closest prior art, such a selection would further imply that this skilled person could pose the objective problem to him or herself. However, this would be at odds with the very aim of the problem-solution approach, namely to provide an objective method of evaluating inventiveness, avoiding as far as possible an inadmissible hindsight analysis. The board was aware of case law which at least implicitly indicates that the skilled person may select their "own" closest prior art (see e.g. T 1841/11, T 2057/12, T 1248/13). However, the board in the case in hand followed the conclusions drawn, for example, in T 422/93 (OJ 1997, 24, see headnote 1) and T 1140/09 that the relevant skilled person was to be defined starting from the objective technical problem. In the board's view, the person skilled in the art within the meaning of Art. 56 EPC entered the stage only when the objective technical problem had already been formulated. Thus, the skilled person under Art. 56 EPC was the person qualified to solve the established objective technical problem (see e.g. T 32/81, OJ 1982, 225; T 26/98; T 1523/11) and not necessarily the person versed in the field of the underlying application or in the field of the selected closest prior art, as apparently advocated in T 25/13. The board concluded that, in accordance with the findings in T 855/15, it must be the respective deciding body (whose members cannot be equated with the skilled person as a notional entity; see T 1462/14) – be it the examining division, the opposition division or the relevant board of appeal – that selects the closest prior art rather than the skilled person mentioned in Art. 56 EPC. The board summarised its finding in a catchword as follows: In the application of the problem-solution approach for the assessment of inventive step, the person skilled in the art within the meaning of Art. 56 EPC enters the stage only when the objective technical problem has been formulated in view of the selected "closest prior art". Only then can the notional skilled person's relevant technical field and its extent be appropriately defined. Therefore, it cannot be the "skilled person" who selects the closest prior art in the first step of the problem-solution approach. Rather, this selection is to be made by the relevant deciding body, on the basis of the established criteria, in order to avoid any hindsight analysis.

In T 787/17 the board determined that D2 came closest to the subject-matter of the invention and therefore served as the "closest prior art" for the purposes of the problem-solution approach. Within D2, the embodiment in Fig. 11a was closest to the invention. The board could not agree with the argument that this embodiment did not amount to a realistic starting point because it did not give the skilled person any indication as to how they were supposed to proceed in order to solve the problem. It stated that, as a rule, any element of the prior art in the field of the invention that disclosed subject-matter developed for the same purpose or with the same aim was a possible starting point. There was no need for special justification, e.g. on the basis of the skilled person's considerations. In particular, whether such an element gave any indication as to how to solve the objective technical problem was irrelevant to its selection as a starting point, for the simple reason that the objective technical problem could only be defined on the basis of the starting point. Nor was there any need to justify why the skilled person would proceed from one particular embodiment among a large number of embodiments in a pre-published document. Each of the embodiments constituted an element of the prior art that was known per se to the (notional) skilled person and could therefore equally serve as a starting point.

In T 172/03 the board had held that the term "state of the art" in Art. 54 EPC 1973 should be understood as "state of technology", and that "everything" in Art. 54(2) EPC 1973 is to be understood as concerning the information which is relevant to a field of technology. It could hardly be assumed that the EPC envisaged the notional person skilled in the (technological) art would take notice of everything, in all fields of human culture and regardless of its informational character. However, the board in T 2101/12 considered that the interpretation of Art. 54(2) EPC given in T 172/03 was incorrect. According to the board in T 2101/12, the legislator would have used a different term if such meaning had indeed been intended. The wording of Art. 54(2) EPC is clear and requires no interpretation. Art. 54(2) EPC itself contains no limitation according to which a non-technical process, such as the signing of a contract at the notary's office, may not be considered state of the art.