While in European nations patentability is often considered in view of a concept called 'Inventive Step' – we don't use this term in the United States. Instead the standard in the U.S. is called 'obviousness'. Obviousness is defined and codified in 35 U.S.C. §103. Of course, the real meat to the definition lies in case law where every detail of every notion imaginable has been tested – and continues to be tested.
Inventive step is defined in Article 56 European Patent Convention. Since Germany and most European nations do not use case law in the manner which the US does, written law is supposed to control the outcome. However, each nation of Europe has their own way of executing the test for Inventive Step. Since the European Patent Office operates under the European Patent Convention, one could expect the same principle to be exercised for each country when having a patent examined at the EPO.
The EPO uses a "problem-solution approach". The following three steps are performed to determine whether an invention includes 'inventive step':
- identifying the closest prior art, i.e., the most relevant prior art;
- determining the objective technical problem, i.e., determining, in the view of the closest prior art, the technical problem which the claimed invention addresses and successfully solves; and
- examining whether or not the claimed solution to the objective technical problem is obvious for the skilled person in view of the state of the art in general.
At the conclusion of this test, the examiner declares whether or not he finds 'inventive step'. In other words: If the skilled person would have been prompted to modify the closest prior art in such a way as to arrive at something falling within the terms of the claims, then the invention does not involve an inventive step. How does an examiner make this determination? The EPO has given guidance on this, but it all gets rather complex.
The U.S. system is not much better. After studying hundreds of important decisions made by the courts over the years, we always get back to the same point where it is difficult to determine what is 'obvious' and what is 'not obvious'.
It is important to remember, the standard is different for US and Europe. When a person drafts a patent application, it is necessary that care is taken to include description which leads to a conclusion of both non-obvious and inventive step if the application will be prosecuted in both the US and Europe.