6.1. Repeatability

In T 281/86 (OJ 1989, 202) it was held that there is no requirement under Art. 83 EPC 1973 according to which a specifically described example of a process must be exactly repeatable. Variations in the constitution of an agent used in a process are immaterial to the sufficiency of the disclosure provided the claimed process reliably leads to the desired products. See also T 292/85 (OJ 1989, 275); T 299/86 date: 1987-09-23 (OJ 1988, 88); T 181/87, T 212/88 (OJ 1992, 28); T 182/89 (OJ 1991, 391) and T 19/90 (OJ 1990, 476).

In G 1/03 (point 2.5 of the Reasons) the Enlarged Board indicated that a lack of reproducibility of the claimed invention is relevant under the requirements of sufficiency of disclosure if the technical effect is a technical feature of the claim, since then it is a feature characterising the subject-matter claimed (T 1079/08). A lack of reproducibility of the claimed invention (i.e. a failure of the claimed features to deliver the effect aimed for) is seen to represent, in the case of an effect which is not expressed in a claim but is part of the problem to be solved, "a problem of inventive step". If an effect is expressed in a claim, there is lack of sufficient disclosure (G 1/03, OJ, 2004, 413, and T 939/92, OJ 1996, 309, cited by T 2001/12, T 1845/14, T 2210/16).

According to established case law, the requirement of sufficiency of disclosure of Art. 83 EPC is not met if an effect expressed in the claim cannot be reproduced (summary of the case law in T 1473/13; see also T 1845/14). T 1473/13 and T 1845/14 were cited more recently in ex parte case T 553/23.

It is also noted that the case law states, with reference to T 1437/07, that the requirement of an enabling disclosure for a prior art document is the same as the requirement of sufficiency of disclosure for a patent (T 1045/21, T 654/20, T 2916/19, T 380/16).