As readers of this blog will be aware, the EPO applies a quite peculiar and unique method to the analysis of inventive step, the “problem-solution approach”. This approach breaks the statutory question of Art 56 whether the invention was, having regard to the state of the art, obvious to a person skilled in the art, down into a 3-step test. This involves (1) the determination of the “closest prior art”, (2) the formulation of the “objective technical problem”, and (3) the assessment whether or not the claimed invention would have been obvious to the skilled person. One might quip that this approach has replaced a single problem (the determination of obviousness/inventive step) with three problems. This is because parties nowadays frequently argue about (i) what the closest prior art was, (ii) what the objective problem was, and of course (iii) whether the invention, expressed as the solution to the objective technical problem, was obvious or not at the priority or filing date. This contribution will focus on question (i), i.e. the question of what is (or should be) the closest prior art, and whether the EPO’s approach towards the closest prior art has changed in the last couple of years.

The jurisprudence of the Boards of Appeal has developed certain criteria for identifying the document which is used as a starting point for the assessment of inventive step, the so-called “closest prior art”. Usually, the closest prior art is the document which shares a common purpose with the invention or aims at the same objective, and which requires the minimum of structural and functional modifications (e.g. T 606/89). The Boards of Appeal of the EPO are quite adamant that this approach is “objective” and rules out hindsight, “if correctly applied”. For example, the Case Law Book states:

According to board of appeal case law (see T 1/80, OJ 1981, 206; T 20/81, OJ 1982, 217; T 24/81, OJ 1983, 133; T 248/85, OJ 1986, 261), the assessment of inventive step has to be based on the objective, not subjective, achievement of the inventor. By starting out from the objectively prevailing state of the art, the technical problem is to be determined on the basis of objective criteria and consideration given to whether or not the disclosed solution is obvious to the skilled person. Although the problem and solution approach is not mandatory, its correct application facilitates the objective assessment of inventive step. The correct use of the problem and solution approach rules out an ex post facto analysis which inadmissibly makes use of knowledge of the invention (T 564/89, T 645/92, T 795/93, T 730/96 and T 631/00). In principle, therefore, the problem and solution approach is to be used; however, if exceptionally some other method is adopted, the reasons for departing from this generally approved approach should be stated.

But let us be honest: At least the closest prior art cannot be determined without hindsight, i.e. without knowing the invention beforehand (ex post facto). This is so almost by definition: How can you determine whether certain prior art is close to or distant from the invention, if you are supposed not to know the invention? So the task is to first determine the closest prior art having knowledge of the invention, to then determine the problem that the invention “objectively” solves vis à vis this closest prior art (again requiring the invention to be known), and then to try to forget the invention completely when judging the third question of obviousness. This may or may not work, but excluding hindsight is probably the most difficult task in the determination of inventive step anyway, irrespective of the methodology used.

The concept of the closest prior art within the problem solution approach has been invented to facilitate and objectivize the examination of inventive step. The facilitation resides in the presumption that if the invention is not obvious starting from the closest prior art document, then it will a fortiori also be non-obvious starting from further remote prior art. Thus, if and when one document can be identified clearly as being closest prior art, the examination of inventive step can be focused and limited on this one document (in combination with any further document from the state of the art). The question is what happens in cases where (a) several documents are (arguably) about equally close to the invention and (b) if no document qualifies as a sensible starting point. In scenario (a), an Opponent was, at least in the past, usually allowed to present multiple attacks for lack of inventive step even if they start from different “closest” prior art documents.

However, one Board of Appeal decision and a subsequent change in the Guidelines for Examination G-VII, 5.1 about 18 months ago has raised concerns that the Opposition Division may take a step-wise approach and select the closest prior art document before proceeding to steps (2) and (3) of the problem-solution-approach. This might, in effect, require that an Opponent identifies his “best case” approach from the very start of the proceedings and focusses on just that one approach. Specifically, the Guidelines now cite T 320/15 stating:

… applying the problem-solution approach from different starting points, e.g. from different prior-art documents, is only required if it has been convincingly shown that these documents are equally valid springboards. In particular in opposition proceedings the structure of the problem-solution approach is not that of a forum where the opponent can freely develop as many inventive step attacks as he wishes in the hope that one of said attacks has the chance of succeeding.

Interestingly, T 320/15 mainly relates to an appeal based on an alleged violation of Opponent’s right to be heard, rather than the assessment of inventive step itself. In addition, the Board itself did not hesitate to start from two different documents. However, the decision has probably made its way into the Guidelines in view of one particular paragraph, which reads (in our translation from French) as follows:

With regard to the second objection, the Board notes that according to the problem-solution approach, the appellant should have selected, in a first step, the most promising document to arrive at the claimed invention. The appellant reproaches the Opposition Division for not having allowed him to make several choices as to the closest prior art document and to substantiate several attacks based on each of those documents. However, there is no indication in the record that the appellant was not given the opportunity to choose a document other than D4 as the closest state of the art. Furthermore, the structure of the problem-solution approach does not consist of a forum in which the appellant can at will develop various attacks based on various documents of the state of the art in the hope that one of them would have a chance of succeeding. Therefore, the second objection must also be rejected.

Thus, T 320/15 does not seem to prohibit an inventive step analysis based on two or even more different prior art documents (thus using two or more problem-solution-approaches), but seems to rather caution against abuse. Also the Guidelines for Examination repeatedly emphasize that multiple starting points can be appropriate. E.g., they state that “there is no need to discuss which document is “closest” to the invention; the only relevant question is whether the document used is a feasible starting point for assessing inventive step”.

At present, T 320/15 seems to not have been used by other Boards to prevent an Opponent from presenting more than one inventive step attack. Therefore, one should not overestimate the practical relevance of this decision, in particular for the appeal stage. This is even more so because several recent decisions rather point in the opposite direction, supporting a more liberal approach for the choice of the starting point for the assessment of inventive step.

Albeit in a somewhat unusual context, the criteria for the determination of the closest prior art were put to a test in T 405/14. In this case, the Appellant argued that the skilled person would never start from document D2 when document D1 was available. This argument relied on the view that document D1, in addition to sharing many features with the claimed invention, also addressed the same problem as the invention, which was (arguably) not the case for D2.

The Board, however, did not agree and concluded that D1 and D2 were both suitable starting points for the assessment of inventive step. In spite of its finding that the claimed subject-matter was not inventive when starting from D1, the Board took the trouble of analyzing the notion of the closest prior art in detail. In particular, the Board observed that, depending on the outcome of the objection for lack of inventive step, the term “closest prior art” encompasses two different meanings (cf. Reasons 18):

On the one hand, when concluding that a claimed invention is inventive, the notion of “closest prior art” seems to rely on the assumption that there exists a metric defining the distance between items of prior art and the invention, and that an invention which is not obvious from the “closest prior art” would a fortiori not be obvious with regard to all other items of prior art which, by definition, are not so close. Independently of the fact that the jurisprudence does not define any such metric beyond indicating what criteria might be considered relevant to it (common features, similar purpose, …), there are frequent situations in which the identification of a unique closest or best starting point is not straightforward or even possible.

The second meaning is often formulated in terms of a requirement for the “closest prior art” to deal with the same problem as the invention. This is intended to avoid hindsight leading to a finding that inventive step is lacking. Here, there is no requirement that the “closest prior art” be unique, because the basic rule is that an invention lacks inventive step if it would have been obvious to the skilled person, without hindsight, for any starting point.

Furthermore, the assumptions underlying the concept of “closest prior art” do not accord well with the general principle, derived from the case law, that, in order to be successful, an objection of lack of an inventive step must establish a complete logical chain of considerations which would lead the skilled person to the claimed subject-matter. This basic requirement opens the door to the elaboration of various scenarios under the well-established problem-solution approach, and possibly relying on different items of prior art as starting points, not even limited to items of prior art dealing with the same or similar problem so long as hindsight is avoided.

Subsequently, the Board referred to T 2057/12. In this earlier decision, the same Board had questioned whether the concept of the “closest prior art” results in an analysis of inventive step which is objective and takes all realistic circumstances into account, or whether it rather excludes documents which would in practice be taken into account by the skilled person. When further investigating this issue, the Board drew the following conclusions (cf. T 405/14, Reasons 19; emphasis added):

Experience teaches that a document which shares a common purpose with a claimed invention, as well as a large number of features, in order to solve the same or a similar problem, will not necessarily allow a convincing objection of obviousness to be raised against that invention, whereas said invention may indeed result, without hindsight, in an obvious manner from an apparently less promising item of prior art. In this respect, all items of prior art considered as starting points which allow the elaboration of a realistic attack under Article 56 EPC may be considered to qualify as “closest prior art”, although this currently accepted terminology is somewhat misleading. The approach thus excludes any abstract notion of metric. It follows that every objection of lack of inventive step has to be assessed on its own merits and that a document selected as starting point cannot be excluded only because some seemingly more promising item of prior art is available.

Where does this leave us?

T 405/14 might suggest that, as a matter of principle, the concept of the “closest” prior art and its primacy in the first step of the problem-solution-approach is fundamentally put into question. If the term “closest prior art” (CPA) involves “no metric”, any document may qualify, provided that there is a logical (obvious) way from there to the invention. Widening the existing concept of the CPA, though, may compromise predictability, which is often praised by practitioners as an important benefit of the problem solution approach.

In any case, the Board’s observations in T 405/14 can be seen as a word of caution against a too narrow concept of the “closest prior art”. A document which concerns the same problem or use, does not necessarily have the most features in common with the invention, but can nonetheless be a suitable starting point for the evaluation of inventive step. This understanding would be fully in line with T 1841/11 wherein the Board held (cf. Catchword):

The closest prior art should relate to the same or at least a similar purpose (or objective) as the claimed invention. Even if prior art relating to the same purpose is available, it is not excluded that a document relating to a similar purpose might be considered to represent a better – or at least an equally plausible – choice of closest prior art, provided that it would be immediately apparent to the skilled person that what is disclosed in the document could be adapted to the purpose of the claimed invention in a straightforward manner, using no more than common general knowledge (Reasons, point 2.6).

If, despite the availability of prior art relating to the same purpose as the claimed invention (here: manufacturing a semiconductor substrate comprising a silicon-germanium film), it is nevertheless considered appropriate to select as closest prior art a disclosure relating to a similar purpose (here: manufacturing a semiconductor substrate comprising a germanium film), at least one claimed feature corresponding to the purpose of the invention will generally appear as a difference over the closest prior art (here: silicon-germanium).

However, this difference is not one which can legitimately be invoked in support of inventive step. The problem-solution approach presupposes that the skilled person has a purpose in mind from the very beginning of the inventive process, which in this case is the manufacture of a known type of semiconductor substrate comprising a silicon-germanium film. Within this conceptual framework, it cannot be logically argued that the skilled person would find no motivation to incorporate silicon-germanium. Moreover, an argument that it would not be straightforward to incorporate this difference into the teaching of the document considered to be closest prior art, or that this would require more than common general knowledge, would not, in such a case, constitute an argument in favor of inventive step, but rather an argument that this document is not in fact a promising starting point.

Similar considerations can be found in T 1518/17 (cf. also T 1841/11). Taken together, these decisions seem to suggest that the “closest prior art” is (or should be) no more and no less than the most “promising springboard” towards the invention (which can, at least in our view, only be determined once the problem-solution-approach has been fully carried out). Also in T 1742/12, the Board effectively treated the terms “closest” and “most promising” as being equivalent and made the following observations (cf. Reasons 6.5):

… a piece of prior art on the basis of which the claimed invention is considered non-obvious cannot be “closer” than a document on the basis of which the claimed invention appears obvious, because it is evident in this situation that the former does not represent the most promising springboard from which to arrive at the invention (see T 824/05, Reasons 6.2).

Based on T 1742/12 and T 824/05, the Guidelines conclude that “the applicant or proprietor cannot refute the argument that the claimed subject-matter lacks inventive step by submitting that a more promising springboard is available”. It was exactly this argument on which the Appellant relied in T 405/14 and which was turned down by the Board.

Taking the above case law into consideration, it seems that the problem-solution-approach has meanwhile matured into a 4-step test, involving:
(1) identifying a reasonable starting point among the available prior art as candidate “closest prior art”;
(2) assessing the technical results (or effects) achieved by the claimed invention and defining the objective technical problem;
(3) examining whether or not the skilled person, having regard to the state of the art, would have modified the embodiment of (1) in the claimed manner in order to solve this problem;
(4) unless (1) to (3) lead to a finding of lack of inventive step, repeating (1) to (3) for any other reasonable starting point among the available prior art until the available reasonable starting points are exhausted or until a finding of lack of inventive step is reached.

This would then no longer be so different from the inventive step approaches taken by at least some national courts in EPC member states. In Germany, for example, the concept that there is a preference of a “closest” prior art and that the examination of inventive step can be stopped once it has been shown that the invention is not obvious starting from the “closest prior art”, has long been dismissed and criticized. The prevailing opinion in Germany is that inventive step must be present vis à vis the entire prior art and should not depend on the choice of the starting point in an individual case.


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  1. The fact that several documents may qualify as closest prior art is not a new insight in the case law of the Boards of Appeal. Rather it has been applied from the outset, see epi information 1997, 25, 28. The problem and solution approach is a tool to simplify the assessment of inventive step but it cannot be used to replace the answer to the legal question whether the invention was obvious to the skilled person. In order to find the right answer, any starting point in this analysis has to be realistic. A typical situation for different realistic starting point may be the search for a vaccine against Covid 19: You may start from a vaccine effective against similar virusses or you may search for a new substance based on the knowledge oft he structure of the new virus. The searches for a new use for a known vaccine or for a new substance useful as a vaccine against an illness may imply several and quite different starting points.
    Quite often the problem and solution approach is labelled as specific to EPO practice, but also German practice, as a rule, starts from a document which is considered as closest to the invention (BGH GRUR 1997, 272, Reasons II.3 – Schwenkhebelverschluss) and continues by examining whether the skilled person would have combined this piece of prior art with further citations leading to the claimed invention. This is also done in decisions criticizing the concept of the closest prior art (BGH GRUR 2009, 1041, notes 20 and 23 – Fischbissanzeiger).

  2. A question (prompted by that first comment). At the EPO, the heart of the PSA is the OTP, the objective technical problem (and the way it is derived). For me, it is only the reliance on the OTP that renders EPO-PSA truly objective and free from ex post facto analysis of obviousness. Does Germany set the OTP at the heart of its obviousness enquiry, I am doubtful.

    It must be kept in mind that the patent attorney of ordinary skill in the art of drafting patent applications has (or can have) the entirety of the public prior art available when framing the invention in the context of the art, and so is unconstrained in the formulation of the problem that the claimed subject matter solves. She will draft in a way that will help the Patent Office to recognise patentability of the widest achievable claim.

    To be fair to the public, and to prevent the issue of claims of undeservedly wide scope, the Patent Office enquiry into obviousness must be arranged so that it cannot help but recognise this real life drafting process. At the EPO, I think it is. Elsewhere, I’m not sure.

  3. Yes, „closest prior art“ is a misnomer and I have the experience that the EPO in practice does allow attacks based on different documents. The only risk I see is that the EPO starts to take the view that there is and can be only one single „closest“ document seriously as it is striving for procedural efficiency. Further, as you point out, the four step test (i.e. the classical problem solution approach used with any promising document as a starting point) is used in many different countries, albeit using a different terminology.

  4. Additionally, what needs to be kept in mind is that the CPA selected by the Applicant should not be the one which is easy to argue. Many a times, people choose the CPA with this approach and therefore, PSA is jeopardised. While this might be an easier way to argue, but it will certainly not be appreciated by the EPO. Having said so, this does not stops us from re-assesing the CPA based on the facts or afresh (not straightaway discussing the CPA designated by EPO). The technical field, purpose, and features should be the sole basis for selecting the CPA and ideally should be repeated for the CPA designated by the EPO as well. This might be a lengthy process, but will certainly make things clear.

  5. This post is welcome as the selection of the closest prior art is an important issue in itself and in addition has broader implications.
    The case law of the Boards of Appeal decisions in this respect has been somewhat erratic. In addition to the decisions cited in the post, some decisions on CII cases have held that the closest prior art was the generic computer – regardless of the specific subject matter of the application/patent (T 807/16, later contradicted by T 697/17). This is to be linked to the doctrine of T 172/03 (Ricoh) excluding non technical information from the scope of prior art as defined in Article 54(2). This doctrine, incorporated in Guideline for Eximination, G VII-2, has been challenged in T 2101/12 (Vasco), which has held this doctrine is incorrect.
    The choice of the word « promising » is somehow unfortunate, as it may suggest that the EPO could view the revocation of a patent as a positive outcome. The EPO should not appear as favouring one side or the other.
    The recent decision T 1666/16 of 23.01.2020 restates the established principle that the closest prior art should relate to the same or at least a similar purpose (or objective) as the claimed invention.
    It is clear that this principle is optimal from the standpoint of objectivity and predictability. Departing from this principle favours uncertainties and additional costs. If « realistic » is viewed as desirable for the choice of the closest prior art, it should imply the objective of paying due attention to « real-life » situations.
    In addition, there is a compelling argument to support this principle, which does not seem to be frequently highlighted. It is the identification of the person skilled in the art, which may be another decisive issue in the problem-solution approach. If the closest prior art does not address the same purpose as the claimed invention, chances are that the « art » of the skilled person will not be the same as that of the closest prior art and as a result will not possess full understanding of the « problem » to be solved. I use quotes for « problem », as the specific problem to be solved i.e. the effect reached by the invention, should not be isolated from the complex of constraints always associated to a certain purpose or objective. The invention, in addition to yielding a specific outcome, must also meet all these constraints, whic eliminates a great deal of possible options.
    As to the statement of purpose, there is a requirement which practitioners must keep in mind, not only in their handling of prosecution and opposition proceedings but also at the source i.e. in the drafting of applications : under the case law of the EPO, the statement of purpose can only be considered if it is a limiting feature of the claim. This requires that the statement of the purpose be linked to elements recited in the claim. It does not suffice to mention the statement of purpose as a possible use of the claimed invention, as is the case when the purpose stated in the claim is preceded by the terms « especially for » (see T 1013/02 of 17.02.2004). There is obviously a price to be paid since making the purpose a limiting feature restricts the scope of the claim to a specific purpose or field of use. That is why many practitioners are reluctant to recite the purpose in the claim as a limiting feature, they may feel this would be detrimental to the applicant’s interests. The results may however be very negative. As a minimum, the application should offer strong support for the purpose or field of use as to provide a fallback position with claim amendment entering the purpose or field of use as a limiting feature.

  6. The choice of the CPA has often been considered as Achilles’ heel off the problem-solution-approach. But it is not as the choice of the CPA has to be done on a reasonable basis.

    It is not for nothing that lot of EQE examiner’s reports consider that the choice of the CPA cannot be based on the document having the most features in common with the claim at stake. The problem to be solved or the claimed use of a device can be determining when it comes to the choice of the CPA.

    It appears to me that at best, there might be one or two documents which come into question when the choice of CPA is to be made. As soon as there are more than three documents as CPA there must be a flaw in the choice of the CPA.

    An opponent will always try to find a CPA which has a lot of features in common and the proprietor a CPA having the least features in common, but this is normal game. In general, it is then the board which will decide what the CPA is.

    In T 2114/16, the opponents considered that there were at least three documents which could serve as CPA, E9, E22 or E26. For the BA only E22 or E26 could be considered as CPA. The BA concluded that the subject-matter of claim 1 was inventive whether E22 or E 26 were considered as CPA as none of the combinations E22+E9 or E26+E9 lead to the subject-matter of claim 1.

    A very good example for the choice of CPA can be found in Paper C of the EQE 2012. Whilst for claim 1 which was quite broad (a patch) there was a choice between different CPA. As soon as one looked at the dependent claims, the choice of CPA narrowed to a single document, as each dependent claim was about a specific use of the patch (therapeutic, analgesic, cosmetic). Paper C of the EQE might be frowned upon as too theoretic, but this paper shows clearly the mechanism leading to a reasonable choice of the CPA.

    There are rare cases in which two documents can serve as alternate CPA, T 591/04. In such a case the differences have to be different, sorry for the pun, as the objective problems and hence the reasoning leading to show a lack of inventive step.

    But one thing is sure in patents 1+2 is different from 2+1. I would thus conclude that in patent matters addition is not commutative….. 😉

  7. I appreciate that the piece is about the starting point but while there are readers I want to pick up and run with the point everybody makes about every obviousness enquiry, that it is inevitably tainted with hindsight.

    Since we can’t avoid hindsight knowledge, the best we can do is recognise that it is inevitable, and work around the problem. Tor me, the elegance of EPO-PSA is that it is compatible with that reality, and really is “objective”.

    The drafter of the patent has hindsight knowledge of the invention and drafts accordingly, choosing the tech field and the problem to optimise patentability.

    The Exam Division searches appropriately, and after that is limited to what is the OTP by what it has found in the search. Applicant is limited to what is disclosed in the patent application, when disputing with the Division the starting point and the OTP.

    When it comes to opposition, both sides slug it out with the best TSM(teaching, motivation, suggestion) arguments they can muster,relative to the OTP, and in this regard both are limited(of course) by the disclosures of documents written prior to the filing date of the application. Both are quick to call out the other side every time its argument relies upon inadmissible hindsight.

    Result: thanks to the OTP and TSM,under EPO-PSA the one (OD or TBA) that is refereeing the fight has an easier task than under any other obviousness methodology, to divine whether the claimed subject matter is inventive or obvious. The arguments relied upon by the opposing sides more or less write the Decision for the OD or the TBA.

    Anybody disagree? .

  8. As said above, the Boards approach is not consisten across the boards. In mechanics and physics, claims need to be inventive over any prior art. Selection of the closest prior art is only done for procedural efficiecy. The closer a prior art is to the subject-matter of a claim, the more likely it is that the claimed subject-matter is obvious when starting from it. Hence, if you invest a lot of time in selecting the closest prior art you subsequently save time on running through the entire process.

    At the chemistry boards the situation is different. Here “the same purpose” or the “same effect” of a prior art is of much more importance than the number of features. If a prior art does not address the same problem, it will be disregarded and the problem solution approach will stop at point 1 for this document.

    I have to say that I have sympathy for this approach because it reflects a more relatistic effort of the skilled person to arrive at the claimed solution. Imagine, claim 1 is a compound claim, a new medicament. for treating hypertension. Two prior art documents are found, one relating to another medicament for treating hypertension, but chemically very different to that claimed. The second document being unrelated to the application’s purpose, showing a paint having a structure very similar to that claimed, possibly only differing by an additional methyl group.

    The most realistic approach would be that the skilled person would have departed from the first document. The objective problem would be the provision of an alternative hypertension medicament. In view of the large structural differences the claimed subject-matter would be inventive.

    If you started from document two, the problem would be to provide an alternative to that paint. Since the claimed compound is structurally very similar to that disclosed, the claimed subject-matter will lack an inventive step over the second document.

    In real life, it will be a pharmacologist or pharmacological chemist working on new drugs and not a paint chemist. Paints will just not be considered as a reasonable starting point for any development in pharmacology. That is, the second approach as practised by the chemistry boards, is a more real life approach reflecting the true effort of the skilled person.

    1. I agree with your sympathy for the PSA, it is a laudable effort to minimise the effects of the inevitable hindsight knowledge of the invention by the examiner and avoid the excess of discretion in combining pieces of prior art which is common e.g. in the US.
      But it should be viewed as a tool which is valid within limits, not as dogma. A main reason for the Achille’s heels of the PSA, as described by Attentive Observer, is the systematic application of the PSA by the EPO. It is like squaring a circle. When it is required to use a tool to a case in which it is inadequate, this causes problems such as distorting the meaning of terms such as closest prior art, person skilled in the art or technical problem.
      The PSA is great when the invention is an improvement, the closest prior art is the thing to be improved. It is not so simple when the invention is a new use. And in the chemical/pharma fields, another problem may be the lack of causal connection between the structure of a molecule or product and the claimed property undermines the credibility of the PSA.
      What I heard from colleagues competent in these fields is that the major issue is not inventive step anyway, but the breadth of the claim, thus an Article 84 issue, and the key factor is the number and diversity of examples in the description sufficient to secure a broad scope.

  9. Historically the PSA has been devised in the chemistry boards of the EPO. It took a while to get adopted by other technical boards, the last to join the movement being the mechanical boards. But nowadays you will rarely find a decision from a TBA in which inventive step is not dealt with according to the PSA.

    I do not agree that the boards in chemistry are better when choosing the closest prior art. It is clear that in chemistry the “same purpose” or the “same effect” is much more prevalent. As already stated, Paper C of the EQE 2012 is very revealing in this respect.

    But this does not mean that it does not play a role in mechanics or electricity/physics. If your application is for a drainage pipe, you will certainly not start with a hair curler or a cheese grater as CPA, even if on the drawing there is no difference to be seen.

    The choice of the CPA is depending on the technical field at stake as eventually it is the person skilled in the art in said field which has to decide whether, in view of the starting point and the further prior art available, the invention was obvious to him or not.

    It can well be that the person skilled in the art is a “composite” person. If the subject matter of the application is a plastic injected light for a car, the person skilled in the art is as well knowledgeable in the field of optics and in the field of plastic injection. In such a situation a starting point could well be a document in the field of car lights or in the field of plastic injection. In T 1160/07 there was a similar situation with respect to a tooth brush handle and a method for moulding a chisel handle.

    It is thus not correct to claim that in areas other than chemistry the choice of the CPA is done merely “for procedural efficiency”.

    On the other hand, Max Drei’s view is quite realistic. In the end, the OD or the BA will take over the stance which appears the most convincing. If there is not request for OP, which is opposition is very rare, and the OD or the BA can buy the argumentation of one of the parties, then a decision can be very quick, and the right to be heard has been respected.

    To speak about a “most promising springboard” when deciding upon the CPA is in my humble opinion not very fortunate, as the idea of hindsight comes immediately to mind.

    I would rather say that it comes to the choice of the CPA the person skilled in the art will choose a document which bears an immediate relationship with the subject-matter claimed.

    That in case of pioneer inventions, there cannot be a CPA as we understand it under normal circumstances is not at stake. In such a situation, the inventor has opened a new field of technology. But in any case, the person skilled in the art has started from a technical situation which was engulfed with problems which he wanted to improve.

    Even in case of a new medical use of a substance or composition, he has started with said substance or composition. That is why in the first case of a new use of a known substance or composition novelty and not inventive step applies.

    The claimed new claimed use/property does not undermine the credibility of the PSA, as this is more than often a question of sufficiency rather than inventive step. If the claim is too broad with respect to what has actually been disclosed, but the description contains at least one workable example, the claim might have to be limited to what has actually been disclosed, i.e. to be properly supported by the original disclosure. In such a situation inventive step comes second.

    If the original disclosure does not make the use/property plausible and essential features have not been disclosed then it is a real problem of sufficiency. If sufficiency is not given, it appears in general moot to discuss inventive step. T161/18 is one of those exceptions as the BA has decided to discuss inventive step after having decided on a lack of sufficiency.

    1. In CII cases, esp. business methods, Boards of Appeal are struggling to reach a consensus on the meaning of such “composite” person skilled in the art. In T 1463/11 it is split between a business person and a technical person, which in my view is entirely artificial and only creates unnecessary issues,, whereas T 2101/12 assumes a legally skilled person aiming at automating a legal process, and holds that the closest prior art is a legal process. This is realistic and allows sound reasoning.
      In the example of a plastic injected light for a car, I would also consider the automobile application as a possibly or likely relevant field of use. To give simpler examples in the mechanics/physics area, if an invention relates to a category of component, such a pressure sensor, the intended field of use should be the primary factor for defining the skilled person and the closest prior art.

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