Inventive Step

Definition of Inventive Step

To be patentable, an invention must involve an inventive step (A52(1) EPC).

An invention is considered to involve an inventive step if, for a person skilled in the art, it is not obvious in view of the prior art relevant to the inventive step (A56 EPC).

Relevant Prior Art

For the definition of relevant prior art, please refer to The definition of relevant prior art.

Proof of Disclosure

Regarding the proof of disclosure, please refer to the page Proof of disclosure.

Assessment of Inventive Step

Combination of Documents

It is entirely possible to combine several documents (rarely more than two, Guidelines G-VII 6) if this combination is obvious to the person skilled in the art (T2/81): e.g., one of the two documents explicitly refers to the other.

Exceptions to this principle may arise in the case of partial problems, where each problem must be addressed separately (Guidelines G-VII 6).

It is also possible to combine two embodiments of the same document if nothing leads the person skilled in the art away from this combination (i.e., « teach away, » T95/90).

Problem-Solution Approach

The EPO has developed an approach to scientifically determine whether an invention involves an inventive step.

This approach is not mandatory but is widely recommended (T465/92, Guidelines G-VII 5).

This approach consists of 5 steps:

• determination of the technical field of the invention to limit the relevant prior art;
• determination of the person skilled in the art;
• determination of the closest prior art;
• determination of the objective technical problem;
• determination of the obviousness of the invention.

Step 1: Technical field and limitation of the prior art

How to determine whether a technical field should be considered for the problem-solution approach?

A technical field is considered relevant to the technological field of the invention:

• if this field represents the same technical field as that of the invention;
• if this technical field represents the common general knowledge of the person skilled in the art (T195/84);
• if this field is a sub-field of the field of the invention (i.e., a narrower specific technical field) and if the main known application of the invention is in this sub-field (T955/90);
• if this field is a « related » field, that is to say:
  • if identical or analogous problems to those encountered in the field of the invention arise, and which the person skilled in the art would normally also be aware of (T176/84);
  • if the materials used are related or when the technical problem arising in both fields has been publicly discussed (T560/89).

It should be noted that the technical field sharing the most features with the invention is not necessarily the one to be retained (even if it is generally appropriate, Guidelines G-VII 5.1).

Furthermore, prior art cited by the applicant themselves is not necessarily relevant for assessing inventive step (T28/87).

Moreover, the mere fact that the description refers to a document from a remote technical field does not allow that technical field to be considered as related (T28/87).

Step 2: Technical Field and the Person Skilled in the Art

The person skilled in the art is the person skilled in the technical field of the invention (Guidelines G-VII 3) (i.e., of its technical problem and not of its solution, T422/93).

For example, if the technical problem is « finding an elastic material that does not break easily, » the person skilled in the art will be a specialist in the field of materials, even if this material is intended for the manufacture of handling straps (T32/81).

The person skilled in the art is understood (Guidelines G-VII 3) to be:

• a practitioner of ordinary skill, an expert in their field;
• who possesses the general knowledge in the relevant field;
• and who has an omniscient knowledge of all elements of the prior art (as previously limited),

to have at their disposal the means and capacity to carry out routine work and experiments.

As we see, the person skilled in the art is a pure legal fiction.

This fiction is all the more pronounced as it is accepted that the person skilled in the art is not necessarily a single individual: they may thus be a multidisciplinary team (for example, to solve several interrelated problems, T141/87 and Guidelines G-VII 3).

While this person skilled in the art is often a person of average qualification (i.e., not a Nobel Prize winner, T60/89) consulting the prior art for a component having the same function (T142/84), they may nevertheless be a PhD student if the technical field so requires (e.g., DNA sequencing, T412/93, Guidelines G-VII 3.1).

Step 3: Determination of the Closest Prior Art

Principle: Same Objective or Same Effects

To determine this closest prior art (i.e., which constitutes the most promising starting point for an obvious development leading to the invention, Guidelines G-VII 5.1), the following must apply:

• this disclosure aims to achieve the same objective or to obtain the same effects as the invention (T482/92, T2255/10);
• or at least that it belongs to the same technical field as the invention (or to a closely related field).

While this disclosure is generally the one that corresponds to a similar use and requires the fewest structural and functional modifications to arrive at the claimed invention (T606/89), this is not a rule (T1666/16): greater weight must therefore be given to the original problem, the intended use, and the effects achieved than to the number of common features in selecting the closest prior art (T1019/13).

Uniqueness of the Closest Prior Art?

Due to the wording « closest, » we may be tempted to conclude that this prior art is necessarily unique.

This is not the case: there may be several instances of the closest prior art (T405/14), or there may be doubt as to the closest prior art (T1148/15).

The relevant question, when choosing a starting point, is essentially whether it allows for raising a realistic objection or not.

A document selected as the closest prior art cannot be excluded simply because another, apparently more promising, is available.

Explicit or inherent effects?

It may happen that a document seeks to solve a completely different problem from the invention (e.g., the anti-dandruff effect of a shampoo) but contains all the features enabling the solution of the invention’s problem (e.g., silicone with a known conditioning effect).

In this case, it may well be selected as the closest prior art document (T2304/16).

Thus, it is not necessary to explicitly seek the technical effect in prior art documents: the mere fact that the prior art inherently possesses the effect is sufficient.

Identification of the purpose of the invention

The determination of the purpose of the invention must not be based on a subjective selection but must take into account what is claimed (T2255/10).

Case of the best starting point

It is not excluded, even when a document D1 addressing the same general technical problem (GP) exists, to consider that another document D2, which addresses a similar problem (SP), constitutes a better choice, or at least an equally plausible choice, provided that it is immediately apparent to the person skilled in the art that what is taught in this document D2 can be adapted to the purpose of the invention in a simple manner and using only their common general knowledge (T1841/11).

Nevertheless, in this situation, it is not possible to argue that the person skilled in the art would not have been motivated to solve the general problem GP starting from D2, as the problem-solution approach presupposes that the person skilled in the art wishes to solve GP from the outset of the inventive process.

Justification of the closest prior art

One may wonder whether the closest prior art must be justified or could be challenged.

In this regard, certain decisions state that no justification is needed (T1112/19) and that all documents may be used indiscriminately.

Focus on closest prior art in another field

It may happen that the preceding analysis leads to selecting a document from a different technical field as the closest prior art.

Under this assumption, it must not be forgotten that closest prior art which does not address the same purpose or the same effect as the invention cannot lead the person skilled in the art in an obvious manner to the claimed invention (T473/15).

Step 4: Determination of the objective technical problem

Introduction

The objective technical problem is the problem that arises, for the person skilled in the art, from the application as filed in view of the objective prior art (T13/84).

This problem must therefore be consistent with the application.

How to formulate it?

Once the closest prior art document has been identified, the technical differences (whether structural or functional) between this disclosure and the claims must be examined.

These technical differences make it possible to formulate a problem that the person skilled in the art would need to address in order to adapt the closest prior art with a view to achieving the technical effects that constitute the contribution of the invention (Guidelines G-VII 5.2): this problem is not necessarily the one presented in the application (it may be less ambitious).

In principle, any effect produced by the invention may be used as a basis for formulating the technical problem, provided the effect can be derived from the application as filed (T386/89).

Of course, the objective technical problem is not the initial technical problem posed by the application and may not be explicitly formulated in the application: it is therefore possible to reformulate it (T13/84) even at a late stage (e.g., in appeal proceedings, T162/86).

The reformulated technical problem may even be based on new effects if the person skilled in the art can see that these effects were implicitly contained in the initial technical problem (T1329/04).

However, it is important to avoid ex post facto reasoning by introducing elements of the technical solution into the technical problem (T229/85), even if this problem is posed by the description itself (T686/18). Similarly, it is important not to introduce into the formulation of the problem a contribution of the patent in identifying an issue (e.g., solving a problem that occurs only rarely and had never been identified by the prior art, T605/20).

Furthermore, if the applicant wishes to introduce the reformulated technical problem into the description, A123(2) EPC must be taken into account (Guidelines G-VII 11).

Inability to formulate

In some cases, the claims may be so broad that formulating the technical problem is impossible due to the multiplicity of possible implementations.

In such a case, the invention cannot be considered to involve an inventive step (T1766/16).

The bonus effect case

An additional difficulty: the case of the « bonus effect ».

A bonus effect occurs when an additional technical effect, even if surprising, is necessarily obtained.

For example, if there is only one option (or a given number of options) for manufacturing a pill and this option necessarily results in a technical effect of uniformizing the pill’s compounds, this uniformization is a bonus effect.

In this scenario, this bonus effect should not be taken into account when formulating the technical problem or in the inventive step reasoning (T1936/13).

The technical problem necessarily technical?

It may happen that some examiners state, « The technical problem you present (e.g., simplifying an interaction) is not technical and is therefore not a real technical problem » (a real-life situation)…

In the absence of knowing what a « technical problem » is (since no one dares to provide a precise definition), case law must be analyzed. Thus, a valid technical problem is one that allows:

• reducing costs (T255/00, point 2.1.2 – in reality, I think the problem should rather be considered as a reduction of a « constraint » by analogy with the decision T102/08);
• increasing audio quality (a subjective characteristic) (T255/00, point 2.1.2);
• simplifying a manufacturing process (T551/09, point 11);
• creating an interactive human-machine interface that is easy to use (T333/95, point 4.2);
• presenting simply and simplifying the evaluation of image search results (T634/00, points 14 and 15);
• improving the appearance of a glass (T1852/09);
• achieving a good compromise between several characteristics (T672/21).

Thus, it is entirely possible for a technical problem to be subjective (e.g., making an object more attractive) (T1852/09 or T255/00).

Furthermore, the fact that the technical problem is motivated by user choices or non-technical preferences has no bearing on whether the problem is non-technical (T634/00, point 15).

Partial technical problems

When the identified technical differences do not all contribute to solving the same technical problem (Guidelines G-VII 6 and T389/86), these are referred to as partial technical problems.

This may occur, for example, in cases of a mere « juxtaposition of features » (i.e., there is no synergy between the different features, Guidelines G-VII 7).

Each partial technical problem will be addressed separately, and a « problem-solution » approach will be applied to each group of features contributing to these partial technical problems (potentially using different closest prior art documents) (Guidelines G-VII 6).

It is sufficient for one of these groups of features to involve an inventive step for the subject matter of the claim to be inventive (Guidelines G-VII 6).

Proof of the technical effect

In certain specific cases, examiners or members of the boards of appeal may question the technical problem posed (by doubting the alleged effect of the feature): this is particularly the case in chemistry, biology, cosmetics, and for pharmaceuticals, etc.

This may also occur in other fields if the claimed technical effect is not credible (T339/13) or is not credible across the entire scope of the claims (T279/17).

This is referred to as the plausibility of the technical effect (T2015/20).

It is then possible to provide comparative tests (T1127/10, potentially upon request T609/02), provided they are verifiable and reproducible.

In particular, if « the description of the procedure and the evaluation of the comparative tests […] are both deficient and insufficiently significant to credibly establish the existence of an improvement« , these tests may not be admissible (T826/11).

A statistical analysis of the results distribution must therefore be provided, particularly where (T826/11):

• experimental results are close and/or
• the panel of testers or the sample size is limited.

There is no requirement as to the timing of submission of these tests: they may be included in the application but may also be provided after the filing, during examination or during an opposition (T2371/13).

The burden of proof lies with the proprietor (T1265/17). Failing this, the examiner will rely on the plausibility of this technical effect.

Step 5: Determining the obviousness of the invention

« Would » approach

Once the technical problem has been formulated, it must be determined whether, in order to solve this problem, modifying the closest prior art to arrive at the invention would have been obvious.

Such a modification will be considered obvious if the prior art as a whole contains a teaching that would have prompted the person skilled in the art to modify the closest prior art to arrive at the invention (Guidelines G-VII 5.3, T90/84).

This prompting or suggestion may, for example, be:

• the second prior art document proposes solving the same technical problem or a similar problem;
• the second prior art document suggests (even implicitly, T257/98) such a modification.

If the closest prior art document discourages a solution (i.e., « teach away » in English, T95/90), it is considered that the person skilled in the art would not seek to modify this document in that direction. This may also be the case if the solution of the invention runs counter to the main teaching of the closest prior art document, in light of the objective pursued by that prior art (T2201/10).

It may also happen that the gap between the closest prior art and the invention is so significant that it would not reasonably allow the person skilled in the art to bridge it (T1571/19).

Abusive « would » approach?

It may happen that some consider the distinctive feature of your invention to be « obvious » and a « clear choice for the person skilled in the art » faced with your problem…

I admit that in the face of such an argument, it is difficult to defend oneself.

By way of illustration, the EPO states that an Examiner may well not cite a document if they consider the feature to be common general knowledge (« Notice from the European Patent Office, dated 1 October 2007, concerning methods in the field of business activities« , OJ 2007, 592).

Fortunately, you can challenge this (T766/91): if someone claims that this feature forms part of the common general knowledge of the person skilled in the art or that the feature is obvious, you can ask them to demonstrate it (I admit I have not had much success before the Examining Divisions, but still… contrary decisions T1370/15 or T1090/12).

« Could » approach: the problem of seeking an alternative or selecting among obvious choices

A technical problem may well be the search for an alternative (« replacement solution« ) to a known feature (Guidelines G-VII 5.2, T12/07, T1968/08, T894/19).

This problem arises if the technical difference from the prior art produces the same effects (or similar effects) as a feature of that prior art (e.g., the technical problem is to find an alternative to using a spring—prior art disclosing rubber for shock absorption, like the spring) (Guidelines G-VII 5.2).

In this situation, it is simply sufficient to prove that the person skilled in the art could have modified (rather than would have modified) the state of the art to arrive at the claimed solution (T1419/10).

« Could » approach: double selection of values without technical effect

As we have seen for novelty, it may be that the novelty over a document lies in the fact that a double selection must be made.

However, if this selection does not produce any technical effect, the invention cannot be considered inventive (T1984/15).

« Could » approach: selection among obvious choices

Negative indicators

Complement to an incomplete disclosure

The invention represents one of the solutions that would readily and/or naturally come to the mind of the person skilled in the art to fill a gap/imprecision in a disclosure (Guidelines G-VII 14).

Use of a known equivalent

e.g., replacing an electric pump with a fuel pump (Guidelines G-VIIA 1).

Use of a material known for its known properties

e.g., using a detergent for its properties of reducing the surface tension of water (Guidelines G-VIIA 1).

Juxtaposition of features

If the features are known independently, function normally without producing an effect that goes beyond the sum of their previously known effects, it is likely that this juxtaposition is not inventive (Guidelines G-VIIA 2).

Positive indicators

Foreseeable disadvantage and prejudice

The mere occurrence of a disadvantageous effect does not imply an inventive step (T119/82).

However, if this disadvantageous effect is in fact merely a prejudice (i.e., a widely held but inaccurate opinion regarding a technical fact), an inventive step may be acknowledged (provided that the existence of the prejudice is proven, T60/82).

Unexpected effect

The achievement of an unexpected technical effect may be considered as an indication of an inventive step (Guidelines G-VII 10.2).

However, if there are no possible alternatives to the distinguishing features of the invention, the EPO will consider this to be a « one-way street » situation in which the use of the feature leads in an obvious manner to foreseeable advantages and thus lacks an inventive step (T192/82).

Long-felt need

Where the invention solves a technical problem for which practitioners have long sought a solution or meets a long-felt need, this may be considered as an indication of an inventive step (Guidelines G-VII 10.3).

Problem invention

An inventive step may be acknowledged where the invention lies in the identification of a problem that was not previously recognized in the prior art (T2/83, T1641/09, T1201/13).

Special case of « mixed » inventions

I invite you to visit the page on mixed inventions.