Feasibility is an independent prerequisite for patentability. It requires that the technical teaching described in the application be disclosed in such a way that a person skilled in the art can reproduce it without undue effort. The applicant is only entitled to a time-limited exclusive right if, in return, they provide the necessary knowledge to enable the invention to be reproduced. If this reproducibility is lacking, there is a fundamental defect in the disclosure, which leads to the rejection of the patent application or, if the property right has already been granted, to its annulment.
This requirement reflects the fundamental exchange between the applicant and the public. The state grants a monopoly for a certain period of time; in return, the general public receives a complete, clear, and sufficient disclosure that allows the invention to be freely used after the patent expires without further research. Therefore, it is not the mere idea that is patentable, but the technically feasible teaching. Only if the application teaches concrete implementation is temporary exclusivity objectively justified.
If this obligation to disclose is not fulfilled, there is no justification for the monopoly. This applies both to the deliberate withholding of essential information and to unintentional omissions that nevertheless prevent the specialist from implementing the teaching. Likewise, there is no feasibility if the claimed concept cannot function technically – for example, because it contradicts the laws of nature – or if the claim is so broad that it encompasses embodiments for which the application does not provide viable guidance. The decisive factor is that the feasibility covers the entire claimed scope: those who claim broadly must teach broadly.
The relevant date for feasibility is the filing date. All information necessary to reproduce the invention must be contained in the documents submitted at that time. Subsequent additions that would introduce essential technical content for the first time are not permitted. Only clarifications that explain what has already been disclosed are permitted, but not new additions. In practical terms, this means that the description, claims, and, where applicable, drawings must be coordinated in such a way that the technical effect and the means of achieving it are comprehensible and reproducible, including the necessary measurement methods, parameter ranges, and boundary conditions.
The assessment is made from the perspective of the "skilled person." This person has average knowledge and skills in the relevant technical field, is familiar with general technical knowledge, and can carry out routine experiments without being inventive themselves. They are neither genius nor naive; they are assumed to have realistic diligence and the ability to evaluate general technical knowledge. Depending on the field of technology, the skilled person may be described differently (e.g., a team from different disciplines), but what remains decisive is always what such a person can glean from the overall content of the application and reliably carry out on that basis.
Finally, feasibility does not require that every experimental instruction be slavishly specified; routine optimizations may be carried out by the skilled person themselves. However, the effort becomes unreasonable where extensive research programs, speculative parameter explorations, or the determination of essential measurement methods would first be necessary. The line is therefore drawn between legitimate completion in accordance with standard practice and the inadmissible addition of inventive work that the applicant himself should have carried out and disclosed. In this way, the requirement of feasibility ensures that patent protection only covers viable, feasible technical teachings – precisely those that actually enable the desired transfer of knowledge and technology to the general public.
From the perspective of this expert, it is examined whether each claim – in its entirety – is supported by the disclosure. If the claim contains variants for which the application does not provide sufficient teaching, it is not feasible in this respect. This can lead to partial or complete invalidity, depending on whether the unsustainable parts can be cleanly separated. Conversely, it is not sufficient to provide only a few particularly well-described examples of implementation if the claim goes far beyond this: the principles and instructions provided must support the generalization.
Another case of lack of feasibility arises when a claimed technical feature or component of the invention is objectively non-functional. This applies in particular to designs that violate established laws of nature, such as a perpetual motion machine that is supposed to perform work indefinitely without an energy supply. Such inventions cannot be executable simply because no expert could put them into practice with the knowledge currently available.