The boards of appeal use the problem and solution approach to determine whether an inventive step is involved. This requires analysis of the invention in terms of a technical solution to a technical problem. Since both the solution and the problem solved by an invention have to be of a technical nature, the problem and solution approach might raise questions when the invention comprises non-technical aspects or elements. Such difficulties are to be resolved by taking due care to define the technical field to which the invention belongs, the scope of technical expertise and skills expected to be applied by the technical person in that particular technical field, and the correct formulation of the technical problem actually solved (T 1177/97). In T 641/00 (OJ 2003, 352), Technical Board of Appeal 3.5.01 had already held that, as a matter of principle, an invention consisting of a mixture of technical and non-technical features and having technical character as a whole was to be assessed with respect to the requirement of inventive step by taking account of all those features which contributed to that technical character. Features of the invention which did not form part of the technical solution to the technical problem had to be disregarded in the assessment of inventive step. In T 531/03 Technical Board of Appeal 3.4.03 confirmed the principles set out in T 641/00 and stated that, in the assessment of inventive step, features relating to a non-invention within the meaning of Art. 52(2) EPC 1973 (so-called "non-technical features") could not support the presence of inventive step. In T 619/02 (OJ 2007, 63), the board confirmed the findings of T 641/00 and T 172/03 that the assessment of inventive step according to the problem and solution approach was fundamentally of a technical nature and, accordingly, the presence of an inventive step could only be established on the basis of the technical aspects of both the distinguishing features of, and the effects achieved by the claimed invention over the closest state of the art.
In T 1121/02 Technical Board of Appeal 3.2.04 also referred to T 931/95 (OJ 2001, 441) and T 641/00 (OJ 2003, 352) and confirmed that features making no contribution to technical character could not support the presence of an inventive step. In T 258/03 (OJ 2004, 575), the board held that the invention was to be assessed by taking account only of those features which contributed to a technical character. The features that made a technical contribution therefore needed to be determined. Finally, the identification of the skilled person also needed careful consideration. The skilled person will be an expert in a technical field (T 641/00). In T 172/03 it was held that the term "state of the art" in Art. 54 EPC 1973 should be understood as "state of technology". The term "everything" in Art. 54(2) EPC 1973 was to be understood as concerning the kind of information which was relevant to some field of technology. It followed that anything which was not related to any technological field or field from which, because of its informational character, a skilled person would expect to derive any technically relevant information, did not belong to the state of the art to be considered in the context of Art. 54 and 56 EPC 1973.
In T 688/05 the board discussed the principles applicable to the examination of inventions comprising non-technical features for inventive step. R. 27(1)(c) and 29(1) EPC 1973 indicated that it had to be possible to express an invention in terms of a solution having technical features to a technical problem. Although a non-technical feature might well serve to define the context in which a technical problem occurred, it could not contribute to its solution since, by definition, it had no technical consequences.