11 March 2021
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The Enlarged Board of Appeal (EBoA) has now issued their decision G1/19, which concerns the conditions under which computer-implemented simulations might meet the criteria for European patent protection.

This is a highly anticipated decision which has attracted a large amount of industry attention, as demonstrated by the 24 amicus curiae briefs filed by third parties. The EPO President also provided submissions, which appeared to take a view which is generally favourable towards the patentability of computer simulations.

The headline news here is that this decision reaffirms, rather than fundamentally changes previous EPO practice in this area. Specifically, the decision makes it clear that the EPO’s existing COMVIK approach to assessing patent eligibility is the correct approach for assessing the patentability of computer simulations, as with any other computer implemented invention. This means that in order to be considered patentable by the EPO, a claimed computer simulation must be novel, inventive and possess “technical character”.

Background: the EPO’s approach to patentability

In general, European patents can be granted for inventions in all fields of technology, provided that they are new, inventive (non-obvious), and susceptible of industrial application. However, there are statutory exclusions for some types of inventions which the EPO considers to be generally non-patentable. This excluded subject matter includes, amongst others, mathematical methods, methods of performing mental acts, and programs for computers (Art 52 EPC).

Nonetheless, even if an invention does pertain to one of the exclusions, a European patent might still be granted under certain conditions, namely if the claimed invention has one or more “technical” features which solve a “technical” problem in a non-obvious manner. However it is not always easy to ascertain the boundary for what might be considered “technical” in the eyes of the EPO. Indeed, it was actually the deliberate intention of the legislator to refrain from defining the terms “technology” or “technical,” due to the viewpoint that an explicit definition might risk unintentionally precluding patent protection for future developments in fields of research which the legislator could not foresee (G 2/07, reasons; T 0489/14, reasons 16). Over a number of years, EPO case law in this area has led the EPO to adopting what is known as the COMVIK approach. The COMVIK approach is outlined in detail in our in-depth study into software inventions at the EPO.

What led to G1/19?

Although case law can often assist in interpreting the statutory exclusions, in some instances diverging interpretations begin to form at the EPO. When these diverging interpretations are identified, it is possible to refer a question(s) to the Enlarged Board of Appeal (EBoA), whose role is to provide a clear decision on which interpretation should be taken, so as to ensure that the law is applied consistently. A Technical Board of Appeal (TBA) recently made such a referral to the EBoA in the interlocutory decision of T 0489/14, which led to G1/19.

The conflicting interpretations in T 0489/14 vs. T 1227/05 (Infineon)

T 0489/14 was concerned with “a computer-implemented method of modelling pedestrian crowd movement in an environment.” The TBA handling this case was minded to refuse the patent application, since they believed that the only “technical” feature was a computer, and that the computer did not solve any technical problem in a non-obvious manner, when considered alone or in combination with the remaining features of the claimed invention (i.e. in combination with the method of modelling). However, the TBA recognised that their reasoning appeared to contradict that of another decision (T 1227/05, “Infineon”) and which is reflected in the EPO Guidelines (G-II 3.3.2).

Infineon was concerned with a computer-implemented method for simulating the performance of a noise-affected circuit. The TBA in Infineon decided in favour of the patentability of the simulation. In particular, they argued that the computer-implemented simulation helped improve the process for designing circuits, and that the implementation on a computer provided technical support that made this possible, noting that:

"Simulation performs technical functions typical of modern engineering work. It provides for realistic prediction of the performance of a designed circuit and thereby ideally allows it to be developed so accurately that a prototype's chances of success can be assessed before it is built. The technical significance of this result increases with the speed of the simulation method, as this enables a wide range of designs to be virtually tested and examined for suitability before the expensive circuit fabrication process starts.

Without technical support, advance testing of a complex circuit and/or qualified selection from many designs would not be possible, or at least not in reasonable time. Thus computer-implemented simulation methods for virtual trials are a practical and practice-oriented part of the electrical engineer's toolkit. What makes them so important is that as a rule there is no purely mathematical, theoretical or mental method that would provide complete and/or fast prediction of circuit performance under noise influences.” (T 1227/05, reasons 3.2.2; emphasis added)

In T 0489/14, the TBA appreciated that there was an “evident analogy” with Infineon, in that “Just as the simulation method claimed in T 1227/05 can be used to predict the performance of a designed circuit in the presence of noise before it is built, so too can the simulation method claimed here be used to predict the performance of a designed environment in the presence of pedestrians before it is constructed.” (T 0489/14, reasons 14)

However, the TBA in T 0489/14 disagreed with the reasoning in Infineon, for two reasons. Firstly, they noted that “although a computer-implemented simulation … can perform a function ‘typical of modern engineering work’, it assists the engineer only in the cognitive process of verifying the design of the circuit or environment”, which is an inherently non-technical process due to the “mental act” exclusion. Secondly, they did not believe that the greater “speed” referred to in Infineon provided a non-obvious technical effect, since any algorithmically specified procedure that can be carried out mentally can also be carried out more quickly if implemented on a computer. (T 0489/14, reasons 15)

The questions

In order to resolve the discrepancy with Infineon, the TBA in T 0489/14 deferred their decision and referred the following questions to the EBoA:

Q1. In the assessment of inventive step, can the computer implemented simulation of a technical system or process solve a technical problem by producing a technical effect which goes beyond the simulation's implementation on a computer, if the computer-implemented simulation is claimed as such?

Q2. [Q2A] If the answer to the first question is yes, what are the relevant criteria for assessing whether a computer-implemented simulation claimed as such solves a technical problem? [Q2B] In particular, is it a sufficient condition that the simulation is based, at least in part, on technical principles underlying the simulated system or process?

Q3. What are the answers to the first and second questions if the computer-implemented simulation is claimed as part of a design process, in particular for verifying a design?

In sum, these questions effectively request guidance regarding the criteria under which a computer-implemented simulation might be considered “technical.” We elaborate further on each question below.

The first question (Q1)

The first question can more briefly be thought of as asking whether computer-implemented simulations are patentable in principle.

The second question (Q2)

If the answer to the first question is yes, the second question essentially requests [Q2A] clarification on what types of features the EPO would consider to be “technical” within a computer-implemented simulation, and [Q2B] whether it is sufficient for the simulation to be based on technical principles.

This question arose because the TBA in T 0489/14 took the interpretation that “a technical effect requires, at a minimum, a direct link with physical reality, such as a change in or a measurement of a physical entity,” and that such a physical link was not present in the claimed invention (T 0489/14 reasons 11). However, they noted that if the EBoA disagreed with this position, then the question would arise as to what is required for a computation to produce a technical effect (T 0489/14 reasons 23).

The Infineon decision indicated that it is sufficient if the simulation concerns an "adequately defined class of technical items". However, the TBA in T 0489/14 did not agree, stating that this appeared to be a clarity requirement (which would not impact the technical nature of the invention), and that they believed that “something more is needed than a (clear) limitation to simulated items that are technical” (T 0489/14 reasons 23).

The third question (Q3)

The third question essentially asks whether the answers to the above questions would change if the invention were claimed to be part of a design process.

This question arose because one of the fall-back positions (Auxiliary Request 4) submitted by the applicant was to amend the claimed invention to not only define the computer-implemented simulation, but also to further require the simulation to be applied in a method of designing a model of a building structure (T 0489/14, reasons 26).

The TBA appreciated that such an amendment would arguably strengthen the applicant’s case, by improving the analogy with Infineon. However, the TBA still believed that the amendment would not contribute to a patentable technical effect since a direct link with physical reality would still be absent (T 0489/14, reasons 26). In particular, they noted that the claimed simulation “helps the designer…. but it does not causally lead to an improved environment design” (T 0489/14, reasons 27; emphasis added).

What are the Enlarged Board’s answers to the questions?

The EBoA applied the COMVIK approach, which led to their responding to the questions as follows:

  • In relation to Q1, the EBoA confirmed that computer-implemented simulations are potentially patentable
  • In relation to Q2A, the EBoA refused to answer this question on the basis that an answer to this question was not required by the referring board, and because they felt that it would “never” be possible to give an exhaustive list of criteria for assessing whether a computer-implemented simulation claimed as such solves a technical problem.
  • In relation to Q2B, the EBoA expressed the view that it is neither a sufficient nor a necessary condition for a simulation to be based, at least in part, on technical principles that underlie the simulated system or process (in order for the simulation to be patentable)
  • In relation to Q3, the EBoA did not see any need to treat simulations differently simply because the simulation is part of a design process


The decision makes it clear that computer simulations can be patented at the EPO, but that such simulations must meet the same patentability requirements as any other computer-implemented invention. This means that in order for a computer simulation to be patented at the EPO, it must be seen as patentable under the COMVIK approach.

As such, a key outcome of G1/19 is that it confirms the primacy of the COMVIK approach at the EPO, when it comes to assessing the patentability of any computer-implemented invention (including, but not limited to, simulations).

This will not lead to a huge change in practice at the EPO. Nonetheless, it is useful to have a decision from the highest level appeal board at the EPO which makes it clear that simulations are patentable at the EPO, and that it is not necessary for a simulation to be based on technical principles that underlie the simulated system in order for patent protection to be obtained at the EPO. This may give confidence to applicants who already have pending applications in the field of computer simulations, as well as to other companies wondering whether they might be able to obtain European patent protection for new inventions in this field.

In relation to T 0489/14 (the appeal case which led to G1/19), the TBA will now need to decide whether the invention under consideration in that case (“a computer-implemented method of modelling pedestrian crowd movement in an environment”) is patentable under the COMVIK approach, after taking due account of the guidance set out in G1/19.


About the authors

This blog was co-authored by James Leach and Juliana Murray.

Juliana is a trainee patent attorney working in our engineering team. She has experience in prosecuting GB and EP patent applications, and collaborating with attorneys in other jurisdictions to help prosecute overseas patent applications. Juliana holds a first class MPhys degree in Physics from the University of Manchester. For her Master’s project, Juliana developed a dual wavelength capillaroscope, which is a new medical imaging device. This research led to a pilot medical trial and is expected to assist with the study of diseases such as Systemic Sclerosis.

James is a Partner and Patent Attorney at Mewburn Ellis. He has a wide range of experience in patent drafting and prosecution at both the European Patent Office (EPO) and UK Intellectual Property Office (UKIPO) across a variety of industry sectors. James has particular expertise in the patentability of software and business-related inventions in Europe.

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