In T 1227/05 (OJ 2007, 574) the application related to a computer-implemented method with mathematical steps for simulating the performance of a circuit subject to 1/f noise. The board noted that while the invention may be preceded by a mental or mathematical act, the claimed result must not be equated with this act. The claims related to a simulation method that could not be performed by purely mental or mathematical means, not to the thought process that led to that simulation method. The board was persuaded that the claimed simulation of a circuit constituted neither a mathematical method as such nor a computer program as such, even if mathematical formulae and computer instructions were used to perform the simulation. The board noted that simulation performed technical functions typical of modern engineering work. It provided for realistic prediction of the performance of a designed circuit and thereby ideally allowed it to be developed so accurately that a prototype's chances of success could be assessed before it was built. The technical significance of this result increased with the speed of the simulation method, as this enabled a wide range of designs to be virtually tested and examined for suitability before the expensive circuit fabrication process started. Without technical support, advance testing of a complex circuit and/or qualified selection from many designs would not be possible, or at least not in reasonable time. Thus computer-implemented simulation methods for virtual trials were a practical and practice-oriented part of the electrical engineer's toolkit. What made them so important was that as a rule there was no purely mathematical, theoretical or mental method that would provide complete and/or fast prediction of circuit performance under noise influences.

As regards the potential exclusion of computer programs, the board stood by its earlier ruling that this exclusion did not apply to computer-implemented methods, see T 424/03. For the above reasons, in the board's view, all steps relevant to circuit simulation – and that included the mathematically expressed claim features – contributed to the technical character of the simulation method.

In this context the board noted that the above conclusion could not be drawn from the mere observation that a claimed method runs faster than a "conceivable" reference method. As it was always possible to conceive of a slower reference method, a mere speed comparison was not a suitable criterion for distinguishing between technical and non-technical procedural steps (see also T 1954/08). If, for example, a sequence of auction steps led to price determination more quickly than some other auction method, that did not necessarily imply that the auction steps contribute to the technical character of the method (see T 258/03).

The board concluded that, as the method according to independent claim 1 or 2 was computer-implemented, it used technical means and by that very token had technical character (see T 258/03, OJ 2004, 575 and T 914/02). The board was persuaded that simulation of a circuit subject to 1/f noise constituted an adequately defined technical purpose for a computer-implemented method, provided that the method was functionally limited to that technical purpose. Specific technical applications for computer‑implemented simulation methods were themselves to be regarded as modern technical methods which formed an essential part of the fabrication process and preceded actual production, mostly as an intermediate step. In that light, such simulation methods could not be denied a technical effect merely on the grounds that they did not yet incorporate the physical end product.

Finally, the computer program according to claim 4 (data medium holding a computer program) had the potential for a technical effect going beyond basic hardware/software interaction in a standard computer. Loaded onto a computer it provides for automatic simulation and evaluation of noise-affected circuits. The computer program thus does not come under the program exclusion (see T 1173/97, OJ 1999, 609, point 6.5 of the Reasons).

In T 953/94, the board found allowable a method of controlling a "physical" process using a mathematical model. However, a reference to an unspecified "physical process" might, according to more recent jurisprudence, be rejected as a "meta-specification" (see e.g. T 1227/05, OJ 2007, 574; T 1147/05; T 1029/06).

In T 1265/09 the board noted that it followed from T 1227/05 that steps relevant to a simulation of a technical item contribute to the technical character of the simulation method only if certain conditions, as cited above, are met. Leaving aside the question of whether these conditions were indeed sufficient to contribute to a technical character, the board noted that, in any case, these conditions were not met in the case at issue, since, in connection with the call handling simulation referred to in claim 1, the telephone call center and, in particular, its performance, were not further specified in the claim and, further, the claimed method did not define the further steps which actually resulted in the stated purpose, i.e. the call handling simulation.

In T 531/09 the board noted that definition of technical processes seemed to exclude simulations, whose very purpose is to replace physical entities by virtual ones. In decision T 208/84 the board had held (at point 5 of the Reasons) that a technical process is different from a mathematical method in that the technical process is carried out on a physical entity and provides, as its result, a certain change in that entity. T 1227/05 went beyond the earlier decision in holding that the simulation of an adequately defined class of technical items could be a functional technical feature. In T 1265/09, referring to T 1227/05, the board left open the question whether it is a sufficient condition for a simulation to be patentable that the simulated items be technical, noting that the simulated system (in that case, call handling in a telephone call center) was not technical, so that the condition did not hold. The present board found itself in a similar situation. It came to the conclusion that the condition was not fulfilled in the case at issue. Simulation of a checkpoint is not inherently technical. The board saw claim 1 according to the main request as defining a simulation, on a computer, of a non-technical process, which happens to include some technical devices, and considered that the only feature that made a contribution to inventive step was the fact that the simulation is performed on a computer.