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Date Published

Note: The information in this part only applies to:

  • standard patent applications with an examination request filed on or after 15 April 2013.
  • innovation patents with an examination request filed on or after 15 April 2013.
  • innovation patents where the Commissioner had not decided before 15 April 2013 to examine the patent.  

For all other standard patent applications/innovation patents, see Effort Required to Perform the Invention.


Subsection 40(2)(a) requires that the specification must provide sufficient information to enable the skilled person to perform the invention over the whole width of the claims, without undue burden or the need for further invention.  

There is little guidance in Australian case law on what is meant by an ‘undue burden’.  The following principles are derived from decisions in the UK and Europe.

The disclosure of an invention is not incomplete merely because a reasonable degree of difficulty is experienced in its performance.  In seeking to perform the invention, the person skilled in the art may carry out ‘routine trials’ and ‘normal routine matters that the they would seek to do and be able to do’, i.e. ordinary methods of trial and error which involve no inventive step - these are generally necessary in applying the teachings of a specification to produce a practical result.  However, it would be an undue burden if the person skilled in the art had to undertake prolonged research, enquiry or experiment, or take an inventive step in order to carry out the invention as claimed. (Eli Lilly & Co. v Human Genome Sciences, Inc. [2008] EWHC 1903(Pat); [2008] RPC 29 at [241])

Consideration of Undue Burden

In considering undue burden, regard should be had to the nature of the invention, and the abilities of the person skilled in the art in which the invention has been made.  Each of these points is discussed further below.  The question can then be asked whether the specification requires the skilled addressee to carry out tests or developments that go beyond the routine. (Eli Lilly & Co. v Human Genome Sciences, Inc. [2008] EWHC 1903 (Pat); [2008] RPC 29 at [241] and Halliburton Energy Services Inc v Smith International (North Sea) Ltd [2006] RPC 2)

Nature of the Invention and the Art in Question

In the context of undue burden, it is necessary to consider the normal expectation of a person skilled in the art wishing to perform the invention disclosed in the specification.  For example, the development time for a new pencil sharpener is likely to be much shorter than the development time for a nuclear fusion reactor.  

Where the specification is particularly complex, and performing the invention would be expected to be accompanied by a great amount of work, it is necessary to keep a balance between the interests of the public and the interests of the applicant.  In this regard, it is necessary to guard against imposing too high a standard of disclosure merely because the subject matter is inherently complex.

Where the invention involves a new principle of general application (see Section 40 Enabling Disclosures) and the claimed technique has broad applicability, if the specification provides an enabling disclosure of one practical application of the principle, implementation of the principle for the purpose of an alternative application may not involve an undue burden.  However, this will depend on the facts of the case and be influenced by the extent to which the information in the specification could be used to develop further embodiments without a major conceptual leap. (Kirin Amgen/Erythropoietin II T 636/97 at [4.5])

Abilities of the Person Skilled in the Art and the Art in Question

The person skilled in the art for the consideration of sec 40(2)(a) is the same as for assessing inventive step (see The Addressee).  

The degree of skill or knowledge to be expected of the person skilled in the relevant art will naturally depend on the complexity of the art in question.  Where the art is especially complicated and difficult, it is inappropriate to consider him to be a workman on the shop floor.  Nevertheless, the hypothetical addressee is not a person of exceptional skill and knowledge, he is not expected to exercise any invention nor any prolonged research, inquiry or experiment.  He must, however, be prepared to display a reasonable degree of skill and common knowledge of the art in making trials and to correct obvious errors in the specification if a means of correcting them can readily be found. (Valensi & Another v British Radio Corporation, (1973) RPC 337)

If there are actual errors or omissions in the specification, the specification will not provide a clear enough and complete enough disclosure unless the person skilled in the art would recognise that there was an error, or information missing, in the specification, and could rectify this without making further invention. (Eli Lilly and Co v Human Genome Sciences, Inc [2008] RPC 29 at [241] referring to Valensi v British Radio Corporation [1973] RPC 337).


Where it is prima facie apparent from the specification or any other material on file (e.g. FERs, matter filed under sec 27 or in a re-examination request) that the person skilled in the art, in trying to perform the claimed invention, would take considerably longer than would be typically expected in the art and/or that inventive ingenuity would be required, this would constitute an undue burden.

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