G 1/19 - Patentability of computer-implemented simulations

When G 1/19 was issued on 10 March 2021, it was long awaited, because one expected that it clarifies whether the simulation of a technical system is a proper technical task, or whether the features of such simulation methods must be ignored in the assessment of inventive step under the COMVIK approach of T 641/00.

Before G 1/19, it was common practice at the EPO to accept that computer-implemented simulations have technical character, as long as the underlying simulated system was a technical one. This practice was mainly based on T 1227/05 (Circuit simulation I/INFENION), which found that:

"[s]imulation of a circuit subject to 1/f noise constitutes an adequately defined technical purpose for a computer-implemented method functionally limited to that purpose" (Headnote 1). 

The Board in T 1227/05 found this rather applicant-friendly approach justified, because simulations are nowadays part of the engineer's toolset and frequently applied in the engineering cycle. The Board stated:

"Simulation performs technical functions typical of modern engineering work. It provides for realistic prediction of the performance of a designed circuit and thereby ideally allows it to be developed so accurately that a prototype's chances of success can be assessed before it is built." (T 1227/05, point 3.2.2 of the reasons)

This applicant-friendly interpretation of the technicality requirement of the EPC was fundamentally put into question by decision T 489/14 (Pedestrian simulation/CONNOR) of 22 February 2019.

The Board in T 489/14 took a more conservative approach to the question of what constitutes patentable subject matter. 

The invention in T 489/14 related to a method of simulating the movement of pedestrians in an environment, such as a building or a train station, wherein the movement of a plurality of pedestrians through the environment was simulated on the basis of "individual paths" that each one of the pedestrians chose was considered (see Figure in the upper right corner).

In principle, the Board in T 489/14 considered that, for a simulation method to be technical, an impact on the "physical reality" is required. They were of the opinion that it is not sufficient for a simulation method to be technical that the underlying simulated system is a technical one. As a general rule, the method itself must have some impact on the physical reality:

"In the Board's view, a technical effect requires, at a minimum, a direct link with physical reality, such as a change in or a measurement of a physical entity." (T 489/14, point 11 of the reasons)

The Board in T 489/14 was well aware that by this statemet they departed from the view taken in T 1227/08. As a consequence, they found it justified that the following questions be referred to the Enlarged Board of Appeals under Art. 112(1)(a) EPC:

"1. In the assessment of inventive step, can the computer-implemented simulation of a technical system or process 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 the first question is yes, what are the relevant criteria for assessing whether a computer-implemented simulation claimed as such solves a technical problem? [b] In particular, is it a sufficient condition that the simulation is based, at least in part, on technical principles underlying the simulated system or process?

3. What are the answers to the first and second questions if the computer-implemented simulation is claimed as part of a design process, in particular for verifying a design?"

The Enlarged Board in G 1/19 generally agreed with the approach taken T 498/14, in that a simulation method - even if it accurately simulates a technical system - must be regarded per se a non-technical activity. The features of a claimed simulation model - even if the model simulates a technical system - can therefore normally not be contribute to the presence of inventive step under the COMVIK approach. Specifically, the Enlarged Board states:

"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." (G 1/19, point 137; emphasis added by me)

A similar statement is made at point 110 of the reasons:

"Following the COMVIK approach, models underlying a simulation form constraints (technical or not) which are not technical for the purposes of the simulation itself." (emphasis added) 

The Enlarged Board, however, conceded that there are exceptions to the principle. The possible exceptions from the general principle (that simulation methods are not technical), however, are relatively narrow. The Enlarged Board only envisaged two scenarios, in which simulation methods can (exceptionally) contribute to the technical character of an invention. These scenarios are:

1. The steps of the simulation method are adapted to the specific computer hardware on which the simulation method is run, and thereby contribute to a technical character of the simulation method.
2. The simulation method forms the basis for a further technical use of the simulation results, such as controlling a technical system,

(see, e.g., point 137 of the reasons; see also points 88, 110, 112, 115).

The fact that there are only very limited exceptions to the overriding principle that simulation methods are not technical, is easily be overlooked in G 1/19. For example when reading the Enlarged Board's answer to the first referred Question of T 489/14, this answer mentions the exceptions, only:

"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." (G 1/19, Headnote I)

Other commentators have interpreted such statements in G 1/19 as meaning that patent attorneys can continue drafting claims to simulation methods without including a concrete technical use of the respective simulation results, as they did before (see here for an example). I think this approach is overly optimistic; if not wrong. The above answer must instead be read in connection with the answer to the second question, wherethe Enlarged Board states:

"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." (G 1/19, Headnote 2)

In other words, the technical effect of the simulation method, if any, must lie elsewhere, namely in one of the two exceptions above, because the Enlarged Board could not envision any other scenario. The general principle remains that simulation methods per se are not technical.

Also, a seemingly positive statement regarding T 1227/05 under point 133 of G 1/19:

"The Enlarged Board agrees with the findings of T 1227/05 and T 625/11 ..."

must be read in connection with the sentences that follow:

"... if they are understood as being that the claimed simulation processes in those particular cases possessed an intrinsically technical function. However, there are 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 constitutes an adequately defined technical purpose for a numerical simulation method if it is 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 do not apply in general." (point 133 of the reasons, emphasis added)

To me, this clearly indicates that the Enlarged Board is not convinced by the conclusions made in T 1227/04. At least the Enlarged Board finds that the conclusions should not be generalised to other cases.

I expect that the rather sceptical attitude of the Enlarged Board in G 1/19 regarding the technical character of simulation methods will have significant impact on the patenting practice of the EPO concerning computer-implemented simulation methods. At the very least, situations in which the EPO examiner accepts a technical contribution of a claimed simulation method for the plain reason that it simulates a technical system are unlikely to occur after G 1/19.

Patent attorneys are well advised - when drafting applications in this field - to include at least one dependent claim making a (concrete) technical use of the simulation result explicit in that claim. This could be, e.g., a claim including the step of using the outcome of the simulation method for controlling a (specific) technical system. This claim to a concrete techical use of the simulation result may well be the only one that is eventually allowed by the EPO. 

Likewise, applicants planning a patent application in the simulation field should consider holding an additional brainstorming session, in which session concrete and useful technical uses of the new simulation model are identified. This should be done - preferably - before the decision to draft and file a patent application is taken.

The full text of G 1/19 can be found here.