As part of the fallout from the recent G1/19 decision, the Guidelines for Examination in the EPO will have to be updated to reflect the new law.  Though there is a bit of a wait until the next update (the latest revisions just came into force on 1 March 2021), the 2022 revision cycle has already begun.

In this article, we look at the existing EPC Guidelines related to simulations and comment on some of the removals, revisions, and additions that are expected to occur as a result of G1/19.  This will be helpful to practitioners trying to understand how G1/19 will apply in the short term.

As we have mentioned elsewhere, the Enlarged Board has now defined a computer-implemented “simulation as such” as “a simulation process comprising only numerical input and output (irrespective of whether such numerical input/output is based on physical parameters), i.e.  without interaction with external reality.” Such a process should be distinguished from a physical simulation (like a wind tunnel experiment) or processes which measure physical values then used for simulations in subsequent steps.  The main features of a computer-implemented simulation can be summarised as (i) a numerical model of a system or process in the form of data that be processed by a computer, (ii) equations representing the behaviour of the model, and (iii) algorithms providing numerical output that represents the calculated state of the modelled system of process (e.g.  by time increments).

There are currently three brief paragraphs in the EPC Guidelines (see Part G-II, 3.3.2) directed to the patentability of simulations.  Given the 68 pages making up G1/19 it seems a safe bet that the amount of guidance will increase, bringing the Guidelines on simulations closer in line with the rest of computer-implemented inventions.

The first relevant paragraph of the current Guidelines reads:

“The computer-implemented simulation of the behaviour of an adequately defined class of technical items, or specific technical processes, under technically relevant conditions qualifies as a technical purpose (T 1227/05).  Examples are the numerical simulation of the performance of an electronic circuit subject to 1/f noise or of a specific industrial chemical process.”

This paragraph is due a rework.  Though the Enlarged Board agreed with the findings of T 1227/05 (“Infineon”) they noted that the patentability of the circuit simulation was based on the specific circumstances of that case and so the “often quoted criterion” from that decision, that a “simulation constitutes an adequately defined technical purpose for a numerical simulation method if it is functionally limited to that purpose”, should not be considered generally applicable.

As we learned from G1/19, simulations are patentable but it is no longer sufficient for the simulation to be of a technical system — rather, it is the outcome of the simulation that imparts the technical character needed to show an inventive step.  Perhaps new guidance might reflect this and include the helpful example where the Enlarged Board referred to T 1798/13 (“Swiss Reinsurance”); if a simulated weather system is used to forecast the value of a financial product (i.e.  a business method) then it will not contribute any technical character.  However, if that same system was claimed in the context of being used to automatically open or close window shutters then it could contribute to the technical character and thus lead to a patent.

Moving to the second relevant paragraph currently in Guidelines G-II, 3.3.2:

“Such computer-implemented simulation methods cannot be denied a technical effect merely on the ground that they precede actual production and/or do not comprise a step of manufacturing the physical end product.”

This still holds water and could be expanded in view of the G1/19 decision.  In fact, as well as claiming a manufacturing step not being required, it is irrelevant whether the system or process being simulated has ever existed or will ever exist.  To quote the Enlarged Board, “like any other computer-implemented method, a simulation without an output having a direct link with physical reality may still solve a technical problem”.  This ties into the answer of Question 3 of G1/19; as no special treatment is given to a simulation claimed as part of a design process, and a direct link with physical reality is not required to solve a technical problem, there is no need to claim a  simulation as merely a step in a greater design process.

Simulating systems that are as yet unrealised improvements of known systems, or even simulating processes which do not occur (or should actually be avoided) in the real world are known as significant applications of simulations.  However, it is also worth noting that avoiding the need to build prototypes is not a technical effect as the decision of whether or not to build these prototypes is actually a business decision made by humans.

Lastly, the third relevant paragraph of the existing Guidelines reads:

“In contrast, the simulation of non-technical processes, such as a marketing campaign, an administrative scheme for transportation of goods or determining a schedule for agents in a call centre, does not represent a technical purpose.  In addition, a generic limitation, such as “simulation of a technical system”, does not define a relevant technical purpose.”

While these specific examples are likely to remain accurate (i.e.  generally not patentable) this passage could also be updated.  Though simulations themselves are not considered inherently technical, one of the key points from G1/19 was that the simulation of a non-technical process can contribute to the technical character of an invention, as seen in the weather forecasting example (simulating a physical, non-technical system) discussed above.  Again, the important factor is whether the outcome of the simulation is used for a technical purpose.

Please do get in touch if you have any questions concerning the new law on computer-implemented simulations and what it might mean for your invention.  Find my contact details on my website profile here or contact us at

GJE Review: Simulations

GJE’s computer technology team have put together a comprehensive collection of content designed to equip your business with insight into simulations and the role intellectual property has in its development.  To view the full collection, click here.