PCT International Search and Preliminary Examination Guidelines
PART III EXAMINER CONSIDERATIONS COMMON TO BOTH THE INTERNATIONAL SEARCHING AUTHORITY AND THE INTERNATIONAL PRELIMINARY EXAMINING AUTHORITY
Appendix to Chapter 13
A13.08.1 One specific method of assessing inventive step might be to apply the so called "problem-solution approach". The approach consists of the following stages:
1. determining the closest prior art (see also paragraph 13.08);
2. establishing the objective technical problem to be solved; and
3. considering whether or not the claimed invention, starting from the closest prior art and the objective technical problem would have been obvious to the skilled person.
Step 1
A13.08.2 The closest prior art is that combination of features derivable from one single reference that provides the best basis for considering the question of obviousness. The closest prior art may be, for example:
(i) a known combination in the technical field concerned that discloses technical effects, purpose or intended use, most similar to the claimed invention; or
(ii) that combination which has the greatest number of technical features in common with the invention and is capable of performing the function of the invention.
A13.08.3 In the second stage one establishes in an objective way the technical problem to be solved. To do this, one studies the claimed invention, the closest prior art, and the difference in terms of features (structural and functional) between the claimed invention and the closest prior art, and then formulates the technical problem.
A13.08.4 In this context the technical problem means the aim and task of modifying or adapting the closest prior art to provide the technical effects that the claimed invention provides over the closest prior art.
A13.08.5 The technical problem derived in this way may not be what the application presents as "the problem," since the objective technical problem is based on objectively established facts, in particular appearing in the prior art revealed in the course of the proceedings, which may be different from the prior art of which the applicant was actually aware at the time the application was filed.
A13.08.6 The expression "technical problem" should be interpreted broadly; it does not necessarily imply that the solution is a technical improvement over the prior art. Thus the problem could be simply to seek an alternative to a known device or process providing the same or similar effects or which is more cost-effective.
A13.08.7 Sometimes the features of a claim provide more than one technical effect, so one can speak of the technical problem as having more than one part or aspect, each corresponding to one of the technical effects. In such cases, each part or aspect generally has to be considered in turn.
Step 3
A13.08.8 In the third stage the question to be answered is whether there is any teaching in the prior art as a whole that would (not simply could, but would) prompt the skilled person, faced with the technical problem, to modify or adapt the closest prior art while taking account of that teaching, thus arriving at something falling within the terms of the claims, and thus achieving what the invention achieves."
A13.08.9 Note that the requirement of technical progress is not a requirement for the problem-solution approach. Nevertheless, according to the problem-solution approach an objective problem can always be formulated ("finding an alternative", "making it easier to manufacture", "cheaper to manufacture") even in the case where there is no technical progress.