Press Communiqué of 10 March 2021 on decision G 1/19 of the Enlarged Board of Appeal

The Enlarged Board of Appeal of the European Patent Office issued decision G 1/19 (Simulations) today in which it held that the established case law on computer-implemented inventions (COMVIK approach) applies to computer-implemented simulations.


The Enlarged Board of Appeal is the highest judicial authority under the European Patent Convention (EPC). Its main task is to ensure the uniform application of the EPC.

European patent application 03793825.5 concerns the computer-implemented simulation of the movement of a pedestrian crowd through an environment such as a building. The Examining Division refused the application on the ground that the invention lacked an inventive step, mainly because it considered the simulation not to contribute to the technical character of the invention. The applicant appealed and, in the proceedings before it, Technical Board of Appeal 3.5.07 referred three questions on the patentability of computer-implemented simulations to the Enlarged Board of Appeal under Article 112(1)(a) EPC (T 489/14, OJ EPO 2019, A86).

Article 52(2) EPC contains a non-exhaustive list of "non-inventions", i.e. subject-matter which is not patentable because it is not technical. This list includes "programs for computers" (Article 52(2)(c) EPC). However, the exclusion from patentability is limited to "the subject-matter or activities as such" (Article 52(3) EPC).

A claim to a computer-implemented invention usually consists of a mixture of technical features (e.g. a computer or a mobile phone) and non-technical features (e.g. a computer program). Such inventions are called mixed inventions.

Whether a mixed invention involves an inventive step is assessed by the European Patent Office using the COMVIK approach (T 641/00, OJ EPO 2003, 352). This requires that only claim features contributing to the technical character of the invention are considered for the assessment of inventive step. Features which, taken in isolation, are non-technical may, in the context of the claimed invention, nevertheless contribute to the technical solution of a technical problem, and thereby to the technical character of the invention (e.g. a computer program controlling a machine to prolong the life of that machine).

Key considerations

The Enlarged Board of Appeal came to the conclusion that the long-established COMVIK approach applies to computer-implemented simulations. It held that such simulations must be assessed according to the same criteria as any other computer-implemented invention, including with regard to the question whether a claimed feature contributes to the invention's technical character. Any technical effect going beyond the normal electrical interactions within the computer on which the simulation is implemented (i.e. any "further technical effect") may be considered for inventive step.

The invention underlying the referral concerned a simulation process comprising only numerical input and output, without any interaction with physical reality (following the referring board's formulation, a "computer-implemented simulation as such"). The Enlarged Board stated that a claimed feature of a computer-implemented invention may contribute to the technical character of the invention not only if it is related to a technical effect in the form of input (e.g. the measurement of a physical value) or output (e.g. a control signal for a machine). Such a direct link with physical reality is not required in every case. In particular, technical effects may also occur within the computer-implemented process (e.g. by specific adaptations of a computer or of data transfer).

For the assessment whether a simulation contributes to the technical character of the claimed invention, it is not decisive whether a technical or a non-technical system or process is simulated.

These principles apply equally if the claimed computer-implemented simulation is part of a design process.


Nikolaus Obrovski
Jeannine Hoppe
Spokespersons of the Boards of Appeal of the European Patent Office

This press release is a non-binding document for media use.

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