As a rule, additional advantages not mentioned in the application as originally filed but relating to a mentioned field of use can also be considered for the purpose of assessing inventive step, provided such advantages do not alter the character of the invention (T 440/91, T 1062/93, T 67/98, T 1983/07, T 1422/12, T 321/16). Conversely, an alleged technical effect of a feature is not to be taken into consideration when formulating the problem to be solved if the effect cannot be unambiguously deduced by the skilled person from the original application in the light of the closest prior art or if it is not at least hinted at in that application (T 440/91 citing T 386/89 and T 344/89; see also T 67/98, T 532/00, T 321/16, T 867/13). The character of the invention is not altered if the technical problem specified in the application as filed is supplemented by such advantages, since the skilled person could consider them on account of their close technical relationship to the original problem (T 440/91, T 1062/93, T 321/16).

In T 235/04 the comparative test report did not allow any conclusion as to whether the technical benefits of the claimed composition vis à vis the closest prior art were achieved within the whole scope of claim 1. The board did not accept the formulation of the technical problem since the purported improvement had not been demonstrated to arise within the whole area that was claimed. When defining the technical problem, an effect cannot be retained if the promised result is not attainable throughout the entire range covered by the claimed subject matter. Therefore, the technical problem needed to be redefined in a less ambitious way (T 626/90, T 1057/04, T 824/07).

In T 259/05 too the board held the claimed improvement to be unproven; it had not been substantiated by tests or plausibly shown in any other way. The ambitious problem formulated could therefore not be considered successfully solved. So the invention as defined in claim 1 was not a successful solution to that technical problem. As a result, the claimed improvement in the method's efficiency could not be taken into account for assessing the objective problem which the patent in suit sought to solve, or the inventiveness involved. The technical problem therefore had to be reformulated less ambitiously.

In T 1188/00 the board found that a reformulation relating to an effect first alleged in appeal proceedings (a more ambitious problem) could not be used to substantiate inventive step unless it was plausibly demonstrated that the alleged effect could be achieved across the whole scope of the claim. The burden of proof for this lay with the patent proprietor (see also T 134/00).

In T 357/02 the technical problem had to be reformulated in a less ambitious manner. In the board's view it followed from the minimalist character of the technical problem objectively arising from the closest prior art, which can only be formulated as a modification of that state of the art, regardless of a success or failure of the measures applied, that almost any modification of the latter process might be regarded as a feasible alternative by the person skilled in the relevant art, and therefore obvious, since each corresponding solution would be equally useful (or useless).

Another aspect was described in T 155/85 (OJ 1988, 87). According to this decision, it was not acceptable to rely on an effect which had previously been described as undesirable and of no value by the applicant, to present it suddenly as possibly representing an advantage from another point of view, and thereby to imply that the technical problem and the considerations of inventive step should take this reversal into account. A redefinition of the technical problem should not contradict earlier statements in the application about the general purpose and character of the invention (see also T 115/89). The board in case T 2245/10 recalled that the definition of a technical problem which was in contradiction to the original teaching was not allowable.