Patentability of computer simulation methods in Europe

In Europe, only inventions with technical character are considered patentable. This entails that only inventions relating to technology may be protected by patents. In this context, technology is understood broadly, including also agriculture and medical devices.

Patentability of computer programs

Computer programs are a key exception in that they have not been considered as being technological entities. Although a large part of the inventions of our time are implemented using computer programs, they may be patented in Europe only in case they have a technical effect in addition to their computer-program implementation. Expressed in other words, a patent won’t be awarded to a new computer program implementing an already known function. For patentability it is key, that the function caused by a program is associated with a technical difference (a difference pertaining to the laws of nature), when compared to prior programs. Hence a new computer-implemented method for controlling an x-ray imaging device, for example, is patentable in case it yields a technical effect in the form of conserved energy or reduced radiation dose, for example.


As an interesting exception to the above, computer simulation of a technical system has been found patentable in decision T1227/05 (INFINEON) of a Board of Appeal of the EPO, despite the simulation not yielding any technical effects outside of the simulation data. This is subject to the provision that the patent application is concretely limited to technical features of the simulated technical system.  In this case, the technical effect of the invention is seen as arising through the technical character of the simulated technical system. In the afore-mentioned case the simulated system was a circuit experiencing 1/f-form noise, and the EPOs internal Guidelines have been updated to reflect this decision.

As a consequence, in light of the prevailing case law, methods of simulating technical systems are patentable in Europe.

Another Board of Appeal, however, has in its decision T489/14 leaned to another direction from the INFINEON case mentioned above. As a result, the question is now pending before the  Enlarged Board of Appeal, EBoA, with case number G1/19. In case the EBoA overturns decision T1227/05, the current situation will change and simulation methods will lose their patentable status in Europe.

Practical consideration

Applicants are consequently advised to carefully consider whether to apply for patents for simulation methods in Europe. There are two reasons for this, firstly, decision T1227/05 sets conditions for patentability of simulation methods, in particular those methods must be clearly connected and limited to simulation of an indisputably technical system, and secondly, T1227/05 itself may be overturned by the Enlarged Board of Appeal.

We will be happy to advise concerning these issues, please contact our expert.

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