12 March 2021 | Chris de Mauny Partner

Chris de Mauny considers the EPO’s Enlarged Board of Appeal decision in G 1/19 (SIMULATIONS).  The Board implicitly endorsed the existing COMVIK approach for computer-implemented inventions and made clear that the same approach applies to simulations, including those used in design processes.


The European Patent Convention (EPC) provides for certain types of subject matter to be non-patentable in article 52(2). This ‘excluded subject matter’ includes “programs for computers” (article 52(2)(c)). However, the subject matter is only excluded “to the extent to which a European patent [or application] relates to such subject-matter … as such”. Thus inventions that include or relate to such subject matter will not necessarily lead to rejection of the application or invalidity of the patent.

The EPO had developed a line of cases, centred on T641/00 (COMVIK) that provided for article 52(2) to be taken into account through the assessment of inventive step. Features of the claim related to excluded subject matter would be identified and then ignored when assessing inventive step. This is referred to as a ‘two hurdle’ approach, referring to what are two separate requirements of article 52 EPC – that of inventive step and that of the invention not being excluded subject matter as such. Thus, a known method implemented via a program for a computer would be unpatentable because it would be obvious over prior art disclosing the same method not implemented via a program for a computer – the program being excluded subject matter would be ignored. 

In around 2006-2008 there was an interaction between the EPO and the English Courts as to the correct application of article 52(2) EPC.  The English Court of Appeal queried the COMVIK approach in the decision of Aerotel, the EPO responded in T154/04 DUNS LICENSING and the Court of Appeal in Symbian acknowledged the different approaches but ultimately was bound to follow its own precedent. However, at that time, the EPO President made a reference to the Enlarged Board of Appeal in G3/08 raising questions about the correct application of article 52(2) EPC to computer-implemented inventions. The reference was, however, refused, although in issuing its refusal the Enlarged Board noted it was “quite comfortable” with the COMVIK approach. 

In this case, the patent application, derived from WO 2004/023347, related to the simulation of a pedestrian moving around an environment populated by e.g. buildings and other persons. It was said to differ from the prior art in that, in modelling the movement of a person, it did not model the movement of a large quantity of persons in a similar way to modelling a fluid but rather sought to account for each individual’s behaviour. The application was rejected by the Examination Division. The appellate Technical Board of Appeal thought that its views on the patentability of computer-implemented simulations differed to earlier case law and, to avoid diverging case law, referred three questions to the Enlarged Board of Appeal (EBA) asking:

(1) In the assessment of inventive step, can the computer-implemented simulation of a technical system … 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?

(2) (A) If the answer [to (1)] is yes, what are the relevant criteria for assessing whether [it] solves a technical problem?

     (B) In particular, is it a sufficient condition that the simulation is based, at least in part, on the technical principles underlying the simulated system…?

(3) What are the answers to [(1) and (2)] if the computer-implemented simulation is claimed as part of a design process, in particular as a verifying step?

Discussion: requirements for ‘technicality’

In interpreting the questions asked, and considering the kinds of simulations that might be relevant, the EBA distinguished a ‘technical system’ as one that “implies than an object is created or a process is run with some purpose based on human creativity”. This was distinguished from a model of a natural phenomena, such as a weather model.

Whether the simulation could produce a technical effect beyond the simulation’s implementation was, according to the EBA something that “can only be understood in the context of the COMVIK approach”. It thus had to produce some effect going “beyond the normal interactions within the computer on which the simulation is implemented”.

Discussing what is meant by different “aspects of technicality in computer-implemented inventions” – e.g. technical features, technical effects, technical character – the EBA concluded it was not possible to exhaustively describe every type of feature that may contribute to the invention’s technical character, but noted features such as the input/output signals, the adaptation of operation within a computer and the like as representing various classes of possible technical things.

Further discussion was addressed to whether an invention would be patentable if it had the potential to produce a technical effect – i.e. an effect that is achieved only when non-technical means (i.e. the program for a computer as such) is used in conjunction. The EBA cautioned against identifying “downstream effects”, being identified as effects of running software, as necessarily implying technical character. Since the underlying patent here related to a simulation, there was also discussion about virtual effects: the case law does not require a ‘tangible’ effect.

Decision: application of COMVIK to simulations

The EBA held that the COMVIK approach is applicable to claims to inventions related to computer-simulations. The same approach of assessing inventive step, outlined above, will apply. In relation to what is being simulated, the EBA held that it did not matter whether that was to be regarded as technical or not – the effect may be technical even if the thing simulated is not, and the reverse may also be true.

Likewise, the mere fact of a claim relating to the use of the simulation in the process of design – rather than as an abstract simulation – may, but may not, be sufficient to confer patentability. For example, the thing to be designed may be technical in nature, but if the difference with the prior art is only that the design is carried out by a process involving a simulation (or even an improved simulation), the claims will likely be obvious or non-novel.

The answers to the questions referred were therefore:

(1) A computer-implemented simulation of a technical system or process that is claimed as such can … solve a technical problem by producing a technical effect going beyond the simulation’s implementation on a computer.

(2) For that assessment is it not a sufficient condition that the simulation is based … on technical principles underlying the simulated system…

(3) The answers to [(1) and (2)] are no different if the … simulation is claimed as part of a design process…

Why is this decision important?

Although not directly asked to consider whether COMVIK is the correct approach, the EBA offered no criticism of COMVIK and proceeded on the basis that COMVIK was the correct approach. It cited the approval of COMVIK in G3/08. It must be acknowledged that the EBA could have gone further than it did, e.g. by expressing firm approval for COMVIK, but the decision implies endorsement of the COMVIK approach.

The EBA’s treatment of whether the COMVIK approach should be applied to inventions relating to computer-simulations implies that all computer-implemented inventions should be treated alike, and assessed in the same way. That applies both where a simulation may be used as part of a control system or other process leading to an automated or part-automated output, or where a simulation is used to assist with design of an article or verify its performance. The breadth of application of the COMVIK approach in the sub-category of simulations implies that the same approach should apply to other kinds of computer-implemented inventions for which some might look for a special rule. A topical example is AI-related inventions. The reasoning of the EBA here implies that the use of an AI system either as part of a control system or a design process should not be subject to any special rule but is subject to COMVIK analysis.

Lastly, the discussion about whether the subject matter of the simulation must itself be technical is interesting. In confirming that it is not sufficient for patentability that the subject matter of the simulation be technical, the EBA also made clear that inventions including simulations of non-technical things may yet be patentable according to the same COMVIK approach – there is again no special category.