A recent High Court judgment of Justice Asher includes some useful comments on tailored discovery and proportionality under the 2012 High Court Rules. While the decisions in Commerce Commission v Cathay Pacific Airways Ltd  NZHC 726 is relatively straightforward, the comments carry weight because Justice Asher was on the Rules Committee that forumulated the new requirements.
The starting point in such a consideration of appropriate tailored discovery orders must be an analysis of the issues. Discovery categories will reflect the issues and will only be ordered for the discovery of documents that are relevant to those issues. Except in exceptional circumstances, these issues will be discernible from a review of the pleadings. Discovery orders that are essentially of a “fishing” nature are not part of tailored discovery. Orders will not be granted where the categories do not relate to a pleaded relevant issue, but rather a non-pleaded issue which might be pleaded should discovery reveal documents that support such a pleading.
Which highlights the importance of getting the pleadings right. It is surprising how much issues can “shift” from those pleaded, especially if insufficient analysis of available documents (usually only your client’s documents, pre-discovery) is carried out before pleading.
Of course, pleadings can be amended, and such amendment is commonplace (in Cathay the Commission was on the 5th version of its statement of claim).
On proportionality, His Honour says:
To determine the proportionality arguments in relation to tailored discovery of particular categories it is necessary to consider the chances of finding relevant documents in the discovery exercise and their degree of relevance. This should then be balanced against the cost of carrying out that discovery process. Broader considerations such as the amount at issue, the resources of the parties, and delay to the proceedings may also be relevant…
It is notable that it is not so much the amount at issue or the resources of the parties that are of primary relevance (though they are still factors), but balancing of the chances of finding relevant documents verus the cost of doing so. As His Honour clearly summarises:
In a decision whether to order discovery under the particular category it is necessary to measure the likely return of relevant documents against the cost of the exercise. If highly relevant documents may be revealed, then a greater cost can be justified.