The Enlarged Board of the European Patent Office has given a momentous decision concerning patentability of computer software inventions


The Enlarged Board of the European Patent Office heard oral arguments in July 2020 concerning patentability of a computer software invention. This rare event was video streamed to over 1600 patent stakeholders and around 8 months later the written decision is available.

What was the patent application about?

The patent application in question was about software for simulating movement of pedestrians in a building such as a train station or hospital; an aim being to aid design of the building.

What are the implications of the decision?

It is extremely rare for the Enlarged Board to consider questions about patentability of software related inventions. The decision is 66 pages long and contains lots of material which will influence patent law in the field for decades to come.

The decision has a dedicated section about “what is technical” and so has implications broadly for all fields of patent law including computer implemented inventions. The decision affirms the COMVIK approach for assessing inventions with a mixture of technical and non-technical features. The decision sets out the two-hurdle approach as being useful for examining computer implemented inventions and explains that it is really a three-hurdle approach. As a result of the decision the case law T1227/05 is superseded.

The EPO Guidelines will need to be updated to take into account the decision and the next update will be around March 2022. It is not clear at this point exactly how the EPO guidelines will be updated.

Two hurdles become three hurdles

EPO case law has for a long time used the two hurdle approach for examining computer implemented inventions. The first hurdle assesses eligibility and is easy to pass by including a feature in the claim which is a piece of computer equipment or a computer-implemented method. The second hurdle is the inventive step hurdle which is difficult to pass since only technical features which contribute to the invention are considered. The Enlarged Board points out that there are really three hurdles. Because there is an intermediate step to find which features contribute to technical character of the invention in view of the closest prior art.

Direct link with physical reality

The referred questions were made by a Board of Appeal and in the referral there are statements about a direct link with physical reality being a requirement for patentability. Often, in the case of computer software, in order to have a direct link with physical reality the claim scope needs to include a step controlling an apparatus in the real world, such as a self-driving car, an x-ray machine or a telecommunications network for example. For many types of computer implemented invention there is nothing in the real world which is controlled or linked to. So having a requirement for a direct link with physical reality would exclude many inventions from patent protection. Thus many Applicants will be pleased to find that the decision includes the statement “the Enlarged Board does not see a need to require a direct link with (external) physical reality in every case”.

Direct technical effects versus potential technical effects

In order to explain why a direct link with physical reality is “not needed in every case” the Enlarged Board used, and therefore endorsed, the term “potential technical effect” used by the referring board. Some of the terminology the Enlarged Board uses is:

Direct technical effect: something that happens in the physical world as a result of features in the patent claim

Potential technical effect: something that happens in the physical world only in combination with non-claimed features

Virtual technical effect: these are “mere data” from models and simulations

The Enlarged Board reasoned that because it is possible to have patents for inventions where there is a potential technical effect, then a direct link with physical reality is not mandatory. The new category of inventions with potential technical effects is large. It encompasses image processing inventions, creating index files for searching in a computer, printer control signals in a text-processing system and all inventions that involve data processing in a way which is independent of a physical apparatus.

COMVIK approach

The Enlarged Board explains that the COMVIK approach is to be used for all claims which include some non technical features and some technical features. In practice that means all patent applications in the field of software will be examined using the COMVIK approach. Having an agreed approach gives legal certainty which is welcomed. Applicants will need to become familiar with the COMVIK approach and plan for it in advance.

Across the whole claim scope

There are several places in the decision where the Enlarged Board says that a specific technical effect is needed across the whole scope of the claim. If the claim scope includes a business use, or a cognitive use, or an educational use then the claim will have to be narrowed before being allowed. Applicants will benefit from including support for narrowing the claim scope in Europe to exclude business uses, administrative used, or cognitive uses which may be within the claim scope on a broad reading by the patent office (even if they are not mentioned in the patent specification).

Criterion of a tangible effect

“The Enlarged Board fully supports the view …that a tangible effect is not a requirement under the EPC”.

As a result of the decision the case law T1227/05 is superseded

There are statements in the decision which indicate that simulation inventions are patentable “only in exceptional circumstances”. Applicants may want to add support for a step of using the simulation results to do something technical in the real world in case that is needed to limit the claims in prosecution.

How were the referred questions answered?

The referred questions are set out below for reference. The answers to questions 1, 2b and 3 proposed by the President of the EPO are given in bold. Those answers were agreed with by the Enlarged Board of Appeal.

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? Yes

2a. 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? This question was not answered as the COMVIK approach is well established for assessing computer implemented inventions.

2b. 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? No

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 answers to the first and second questions are the same.


The Enlarged Board has given a very clear, well-reasoned decision which gives legal certainty in that it endorses the COMVIK approach. The decision is likely to define the law in this field for many years.