2022 updates to EPO Guidelines for Examination – Computer simulation, design or modelling – following G1/19

6. Computer simulation, design or modelling – following G1/19

This forms part of a wider report on the 2022 updates to EPO Guidelines for Examination.


The section of the Guidelines relating to patentability of computer simulation (Part G, Chapter II, section 3.3.2) has been changed significantly following the comments of the EPO’s Enlarged Board of Appeal in decision G1/19.

The Enlarged Board explained that computer simulation should not be treated as a special case of computer-implemented invention, and so computer-implemented methods of simulating, design or modelling will now be examined in the same way as other computer-implemented inventions.


The new Guidelines contain this wording:

Simulations interacting with the external physical reality

Computer-implemented simulations that comprise features representing an interaction with the external physical reality at the level of their input or output may provide a technical effect related to this interaction. A computer-implemented simulation that uses measurements as input may form part of an indirect measurement method that calculates or predicts the physical state of an existing real object and thus make a technical contribution regardless of what use is made of the results.

Purely numerical simulations

A computer-implemented simulation without an input or output having a direct link with physical reality may still solve a technical problem. In such a “purely numerical” simulation, the underlying models and algorithms may contribute to the technical character of the invention by their adaptation to a specific technical implementation or by an intended technical use of the data resulting from the simulation.”

Specific technical implementation of a numerical simulation

The technical contribution that may be made by a model or algorithm because of their adaptation to the internal functioning of the computer system or network on which they are implemented is assessed in the same manner as adaptations of mathematical methods to specific technical implementations, see G II, 3.3.

Intended technical use of the calculated numerical output data of a numerical simulation

Calculated numerical data reflecting the physical state or behaviour of a system or process existing only as a model in a computer usually cannot contribute to the technical character of the invention, even if it reflects the behaviour of the real system or process adequately.

Exceptionally, the calculated numerical data may have a “potential technical effect”, which is the technical effect that would be produced when the data is used according to an intended technical use. Such a potential technical effect may only be relied on for the formulation of the objective technical problem if the intended technical use is either explicitly or implicitly specified in the claim.

If the data resulting from a numerical simulation is specifically adapted for an intended technical use, e.g. it is control data for a technical device, a potential technical effect of the data can be considered “implied” by the claim. The specific adaptation implies that the claim does not encompass other non-technical uses because the intended technical use is then inherent to the claimed subject-matter over substantially the whole scope of the claim.

On the other hand, if the claim also encompasses non-technical uses of the simulation results (such as gaining scientific knowledge about a technical or natural system), a technical effect is not achieved over substantially the whole scope of the claim. Then the potential technical effect cannot be relied on in the assessment of inventive step.


Whether a simulation contributes to the technical character of the claimed subject-matter does not depend on the quality of the underlying model or the degree to which the simulation represents reality.

However, the accuracy of a simulation is a factor that may have an influence on an already established technical effect going beyond the mere implementation of the simulation on a computer. It can be that an alleged improvement is not achieved if the simulation is not accurate enough for its intended technical use. This may be taken into account in the formulation of the objective technical problem (Art. 56) or in the assessment of sufficiency of disclosure (Art. 83), see F III, 12. Conversely, a technical effect may still be achieved by a method where certain simulation parameters are inaccurate but sufficient for its intended technical use.

Design processes

The aforementioned principles apply equally if a computer-implemented simulation is claimed as part of a design process.”

The 2022 Guidelines update deletes some previous positive references to the reasoning in Board of Appeal case T1227/05 (Infineon’s simulation of a circuit). This was expected, in view of the EPO Enlarged Board of Appeal’s lack of enthusiasm for the specific reasoning of the Infineon case. However, it will be helpful if the EPO provides other positive examples of the types of computer simulation claims that are allowable, as we believe the Guidelines should reflect the positive outcomes we are achieving in practice. This would balance a potentially negative impression given by the most recent published simulation decisions of the Technical Boards of Appeal.

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