3.4.2 Most promising springboard

In T 254/86 (OJ 1989, 115) the board described the objectively closest prior art as the "most promising springboard" towards the invention available to the skilled person (see also T 282/90, T 70/95, T 644/97, T 1939/12, T 369/12).

In T 824/05 the board was faced with the situation of two alternative starting points equally suitable for the assessment of inventive step, whereby one starting point, i.e. D11, lead to the conclusion that the claimed subject-matter was obvious and the other starting point, i.e. D1, gave the opposite result. The board held that in this situation D1 did not qualify as the closest state of the art because it did not represent the most promising springboard towards the invention.

In T 1742/12 the board held that if a piece of prior art could be identified as the "closest" prior art or the "most promising springboard" and it could be shown that, starting from this prior art, the claimed invention was non-obvious, then the claimed invention could only be even less obvious starting from any other piece of prior art, and therefore a detailed inventive step assessment starting from the other prior art could be dispensed with. However, the choice of the closest prior art may not always be unambiguous and, in such a case, the problem-solution approach may have to be repeated starting from other pieces of prior art (see T 710/97).

In T 64/16 the board expressed the view the problem-and-solution approach did not require a selection of the "most promising" springboard to the exclusion of any other document. In practice, it makes sense to limit this investigation to prior-art items that are at least "promising" in that potentially a realistic path exists from the prior-art item towards the invention. In many cases, only one "closest" prior-art item needs to be considered because all other available documents are objectively further removed from the invention (see also T 570/91, T 1742/12).