Courts have applied various formulations of the test for inventive step when seeking to answer whether the invention involves an inventive step or is obvious. Whether an invention is or is not obvious is a decision on the facts of the case. Courts have expressed doubt as to whether there is any verbal formula appropriate for all classes of claims (Johns-Manville Corporation's Patent [1967] RPC 479 at pages 93 and 94, per Diplock LJ; approved in Aktiebolaget Hassle v Alphapharm Pty Ltd (2002) 212 CLR 411). The various formulations of the test for inventive step reflect the reasoning process concerning factual issues. Discussed below are how the various formulations are applied.

“Matter of routine” approach and the “Cripps question”

The following tests have typically been used by courts to establish obviousness:

Wellcome Foundation Ltd v VR Laboratories (Aust) Pty Ltd (1981) 148 CLR 262 at page 286 (“Matter of routine” approach):

"The test is whether the hypothetical addressee faced with the same problem would have taken as a matter of routine whatever steps might have led from the prior art to the invention, whether they be the steps of the inventor or not."; and

Aktiebolaget Hassle v Alphapharm Pty Ltd (2002) HCA 59; (2002) 212 CLR 411 approved Olin Mathieson v Biorex (1970) RPC 157 (“Cripps question”):

"Would the notional research group at the relevant date, in all the circumstances, ... directly be led as a matter of course to try [the claimed invention] in the expectation that it might well produce [a solution to the problem]?".

This approach is only appropriate when there is a problem to be solved, being either a problem that is recognised in the art or a problem that is reasonably inferred from the specification. Where the invention lies in the identification of the problem, the “obvious to try” approach will not be appropriate.

It should be noted that “obvious to try” is qualified by the requirement that there is a reasonable expectation that the solution might well solve the problem.

When applying this test, examiners need to appreciate that there will often be many possible solutions to a problem. Not all solutions can be regarded as obvious. Some possible solutions will be likely to solve the problem, while others will be highly speculative. There may be more than one solution which can be regarded as obvious. The question that needs to be considered is whether there is a reasonable expectation that the solution will solve the problem.

The reasons why there would be a reasonable expectation could be:

the solution is known in analogous systems;
the art is highly predictable; or
the prior art suggests that the solution will work, although it has not been confirmed in an example.

The reasons should be provided in support of the objection. For example:

“The problem relates to identifying compounds with antibacterial activity. The citation teaches that compounds of formula II will have antibacterial activity, although there are no examples confirming this prediction. In light of this disclosure, it would have been obvious to try compounds of formula II in the expectation that they would have antibacterial activity.”

Other formulations of the test for inventive step include asking, in the context of the problem the invention is seeking to address (see 5.6.6.4 Assessment of Inventive Step), whether the claimed invention is one of:

a technical equivalent;
a workshop improvement;
an obvious selection;
an obvious special inducement; or
an obvious combination of features of common general knowledge.

Technical equivalents

If a claim is a mere technical equivalent of the prior art, it will not be inventive.

A technical equivalent occurs when integers of a claim replace one or more features of the prior art, and:

the characteristics of the replacement are part of the common general knowledge of the person skilled in the art and provide the same functionality in the context of the problem;
the replacement of the prior art feature would occur at once to the person skilled in the art (Allsop v Bintang 15 IPR 686, (1989) AIPC 90-615; Elconnex Pty Ltd v Gerard Industries Pty Ltd (1993) AIPC 90-984);
the combination as a whole retains the same functionality in the context of the problem; and
there are no problems or difficulties to be overcome in making the replacement.

Where there is a choice of technical equivalents, the choice of one over the others is irrelevant, except where there was no special inducement to choose that one and it has a surprising advantage (see Selections below).

The substitution of an integer in combination with a technical equivalent will not give rise to an inventive step unless a new combination results (Winner & Anor v Ammar Holdings Pty Ltd 25 IPR 273 at page 294).

The test for determining whether a new combination has been made, and hence whether an inventive step exists, is whether the essential character of the device or process has been changed (May v Higgins (1916) 21 CLR 119 at page 123).

Workshop improvements

If a claim is a mere workshop improvement over the prior art, it will lack an inventive step.

A "workshop improvement" refers to an alteration to an existing device which the person skilled in the art would have come to as a matter of routine, "proceeding along previous lines of inquiry and having regard to what was known or used" (Nicaro Holdings Pty Ltd v Martin Engineering Co. 16 IPR 545).

A workshop improvement can occur:

where the prior art fully solves the identified problem. That is, if the person skilled in the art would readily recognise a practical difficulty in that solution, and that practical difficulty would be readily overcome by the person skilled in the art appraised of the common general knowledge (however, see Practical Difficulties Overcome below);
where the prior art does not provide a solution to the identified problem. That is, if the solution would at once suggest itself to the person skilled in the art (see Fallshaw Holdings Pty Ltd v Flexello Castors and Wheels Plc 26 IPR 565 and Winner v Ammar Holdings Pty Ltd 25 IPR 273); or
where the prior art solves an analogous problem in a related area of technology and the person skilled in the art would recognise that the same solution could be applied to the problem with there being no practical difficulty in implementing that solution.

It may be difficult to determine when a feature is a "mere workshop improvement" and when it involves an inventive step as the precise characteristics or quality which distinguishes an invention from a workshop improvement is not clear (Samuel Parkes & Co. Ld v Cocker Brothers Ld (1929) 46 RPC 241 at page 248). In these cases, balance of probabilities considerations apply (see 5.6.1.4 Balance of Probabilities Standard).

Possible solutions to the problem

Single solution

An inventive step objection will apply if:

there is only one option the person skilled in the art would consider in solving either the identified problem or any subsequent practical difficulty;
that option would at once suggest itself to the person skilled in the art, for example if the option is part of the common general knowledge or clearly indicated in the prior art in light of the common general knowledge;
there is no practical difficulty in implementing that option; and
neither the prior art, nor the common general knowledge teaches away from the solution.

Several solutions

Where instead of only one option there are several options which a skilled person would consider and the other considerations discussed above remain the same, an inventive step objection will equally apply.

In this situation, the options are solutions which are “lying in the way” such that the skilled person who takes the ordinary route will be likely to come upon them (Elconnex Pty Ltd v Gerard Industries Pty Ltd 105 ALR 247 at page 262; Philips (Bosgra's) Application [1974] RPC 241 at page 251).

Practical difficulties overcome

There may be situations where the solution is an obvious path to follow yet there were practical difficulties in putting that solution into effect which required inventive ingenuity to overcome. It is noted that a solution that “would be worth trying” (rather than being obvious to try with a reasonable expectation of success) is no longer a valid test of obviousness (Aktiebolaget Hassle v Alphapharm Pty Ltd (2002) HCA 59; (2002) 212 CLR 411).

In most situations, examiners will be unable to determine whether there were any difficulties implementing the solution, unless the specification discusses them explicitly.

Examiners can assume that there were no practical difficulties in implementing the solution and raise an inventive step objection if the claimed invention is otherwise obvious. Submissions in which there were practical difficulties overcome in implementing the solution are to be assessed on their merit. Examiners are to apply balance of probability considerations when this issue is raised (see 5.6.1.5 Application of the Balance of Probabilities in Examination).

Bonus effect

It may be that in following the one obvious option, a bonus and unforeseen effect is produced. However, the presence of that bonus effect (or new and surprising effect) does not in itself give rise to an inventive step as the person skilled in the art would have inevitably arrived at that solution (Asahi Kasei Kogyo KK v WR Grace & Co. (1992) AIPC 90-847 at page 38,089).

Examiners are to be aware that the existence of a bonus effect can usually only be established by evidence.

Selections

Combinations of common general knowledge

Where the claimed invention is directed to a particular combination of features, an objection of lack of inventive step applies if the combination, considered as a whole, is obvious to the person skilled in the art having regard to the common general knowledge. It is insufficient to dissect a claimed invention into component integers and establish that these integers are each a piece of common general knowledge. Examiners must also establish that the selection of those integers is obvious to the person skilled in the art in the context of solving the problem:

"The proper question is not whether it would have been obvious to the hypothetical addressee who was presented with an ex post facto selection of prior specifications that elements from them could be combined to produce a new product or process. It is rather whether it would have been obvious to a non-inventive skilled worker in the field to select from a possibly very large range of publications the particular combination subsequently chosen by the opponent in the glare of hindsight and also whether it would have been obvious to that worker to select the particular combination of integers from those selected publications. In the case of a combination patent the invention will lie in the selection of integers, a process which will necessarily involve rejection of other possible integers. The prior existence of publications revealing those integers, as separate items, and other possible integers does not of itself make an alleged invention obvious. It is the selection of the integers out of, perhaps many possibilities, which must be shown to be obvious. ... The opening of a safe is easy when the combination has been already provided."

Minnesota Mining and Manufacturing Co. v Beiersdorf (Australia) Limited (1980) 144 CLR 253 at page 293.

Selections which are clearly indicated by the prior art in light of common general knowledge

Where a claimed solution:

is one of several possible solutions;
has no special inducement or reason for choosing the claimed solution; and
there is a surprising and unexpected advantage in the claimed solution

then the solution is not obvious. The person skilled in the art would not have been "directly led to the invention".

Where there are a number of solutions to a problem and the claimed solution has advantages over the other solutions, the issue arises of whether the person skilled in the art would have chosen that solution over the others.

Similarly, where the invention claimed is a selection from a known field, and there are advantages in that selection, examiners must determine whether the person skilled in the art would have chosen that selection.

The claim lacks an inventive step if:

the person skilled in the art would have adopted the particular solution or chosen the particular selection on the basis of a special inducement; and
there is no practical difficulty in implementing the particular solution or in producing the selection claimed.

Special inducements occur when:

the prior art teaches towards the solution;
when the common general knowledge teaches towards the solution, or teaches away from the other solutions; or
when the other solutions are impractical.

It is not necessary to establish that success is certain or "clearly predictable" provided the person skilled in the art would be directed to a particular solution and it was clear to the person skilled in the art that it might well produce a solution to the problem (see Wellcome Foundation Ltd v VR Laboratories (Aust) Pty Ltd (1981) 148 CLR 262 at page 267).

Examples of special inducement

Example 1

If there are 2 enantiomers of a compound, the person skilled in the art will recognise that one of the enantiomers will usually have a higher activity than the other. The person skilled in the art would be led to test both enantiomers to determine which of the enantiomers is more active. Provided there has been no practical difficulty overcome in separating the enantiomers, an objection of lack of inventive step will apply.

Example 2

The claimed invention has a certain concentration of a particular constituent and uses this constituent to maximise an effect. The prior art discloses a lower concentration, but notes that the concentration of this constituent influences that particular effect. If the problem addressed by the claimed invention is to maximise the effect, there is a special inducement to raise the concentration and hence there is a lack of inventive step.

5.6.6.3 Tests for inventive step

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