i) Computer-implemented simulation methods 

G 1/19 concerned the computer-implemented simulation of the movement of a pedestrian crowd through an environment such as a building. The questions of law referred to the Enlarged Board of Appeal were answered as follows:

1. A computer-implemented simulation of a technical system or process that is claimed as such can, for the purpose of assessing inventive step, solve a technical problem by producing a technical effect going beyond the simulation's implementation on a computer.

2. For that assessment it is not a sufficient condition that the simulation is based, in whole or in part, on technical principles underlying the simulated system or process.

3. The answers to the first and second questions are no different if the computer-implemented simulation is claimed as part of a design process, in particular for verifying a design.

In the Enlarged Board's opinion, the COMVIK approach was suitable for the assessment of computer-implemented simulations. Like any other computer-implemented inventions, numerical simulations may be patentable if an inventive step can be based on features contributing to the technical character of the claimed simulation method. When the COMVIK approach is applied to simulations, the underlying models form boundaries, which may be technical or non-technical. In terms of the simulation itself, these boundaries are not technical. However, they may contribute to technicality if, for example, they are a reason for adapting the computer or its functioning, or if they form the basis for a further technical use of the outcomes of the simulation (e.g. a use having an impact on physical reality). In order to avoid patent protection being granted to non-patentable subject-matter, such further use has to be at least implicitly specified in the claim. The same applies to any adaptations of the computer or its functioning. The same considerations apply to simulations claimed as part of a design process.

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 a technical effect going beyond the simulation's implementation and may therefore be taken into consideration in the assessment under Art. 56 EPC (see also T 489/14 of 26.11.2021).

A simulation is necessarily based on the principles underlying the simulated system or process. Even if these principles can be described as technical, the simulation does not necessarily have a technical character. The Enlarged Board was of the opinion that it is neither a sufficient nor a necessary condition that a numerical simulation is based, at least in part, on technical principles that underlie the simulated system or process.

In coming to its decision, the Enlarged Board also looked at the decision in T 1227/05 (OJ 2007, 574), which had dealt with an application relating to a computer-implemented method with mathematical steps for simulating the performance of a circuit subject to 1/f noise. The solution was based on the notion that 1/f noise can be simulated by feeding suitable random numbers into the circuit model. In the deciding board's view, the simple generation of the random numbers and the possibility of calculating them separately, before the start of the circuit simulation, provided for a resource-efficient computer simulation. In its analysis under Art. 56 EPC, the board explicitly relied on the COMVIK approach, finding that the simulation of a circuit subject to 1/f noise constituted an adequately defined technical purpose for a computer-implemented invention "provided that the method is functionally limited to that technical purpose". In view of the method's functional limitation to the simulation of a noise-affected circuit, the board came to the conclusion that such simulation could be considered to be a functional technical feature. The board also made clear that the metaspecification of an (undefined) technical purpose could not be considered adequate.

In G 1/19 the Enlarged Board, regarding T 1227/05, stated that calculated numerical data reflecting the physical behaviour of a system modelled in a computer usually cannot establish the technical character of an invention in accordance with the COMVIK approach, even if the calculated behaviour adequately reflects the behaviour of a real system underlying the simulation. Only in exceptional cases may such calculated effects be considered implied technical effects (for example, if the potential use of such data is limited to technical purposes). However, the Enlarged Board stated that its role was not to re-assess decision T 1227/05, which was taken in the specific circumstances of the case. It also noted that the board in T 1227/05 did not rely for its decision solely on its findings that the simulated system was a technical system and that the system could only be understood and modelled by relying on technical considerations.

The Enlarged Board in G 1/19 also referred to T 625/11, which concerned a method for establishing by a computer system at least one limit value for at least one operational parameter of a nuclear reactor, which method included a simulation step and resulted in numerical value(s) for one or more limit values for e.g. global power P of the reactor. The board in T 625/11 considered that the relevant questions were the same as in T 1227/05 and ultimately followed the conclusions of that decision, accepting that the calculated limit values for the operation of a nuclear reactor conferred a technical character to the invention. The Enlarged Board agreed with the findings of T 1227/05 and T 625/11 if they were understood as being that the claimed simulation processes in those particular cases possessed an intrinsically technical function. However, there were rather strict limits for the consideration of potential or merely calculated technical effects according to the COMVIK approach. The often-quoted criterion of T 1227/05 that the simulation constituted an adequately defined technical purpose for a numerical simulation method if it was functionally limited to that purpose should not be taken as a generally applicable criterion of the COMVIK approach for computer-implemented simulations, since the findings of T 1227/05 were based on specific circumstances which did not apply in general.

The Enlarged Board in G 1/19 also referred to T 1265/09. The case concerned computer-implemented methods of determining an efficient schedule for a plurality of scheduled agents in a telephone call centre. The effect of an efficient schedule was found to be a business aim which did not necessarily imply any technical effects The Enlarged Board stated that in T 1265/09, as well as in T 531/09, the negative assessment under Art. 56 EPC was (or could have been) based on the lack of a technical effect by the simulation rather than on the non-technical nature of the simulated system.