Conducting Efficient Patent Litigation Discovery

Article co-written by Yuri Levin-Schwartz, Ph.D., a law clerk at MBHB.

The costs associated with discovery, and particularly electronic document discovery, in patent litigation can be effectively controlled with upfront planning, preparation, and coordination between in-house and outside counsel. Presented in this two-part article are some practical considerations for conducting efficient document collection and review. In this first part, early collection activities and agreements with opposing counsel are discussed. In the second part, developing and implementing a collection plan and reviewing documents will be discussed.

Early Collection Activities

Discovery cost control and efficiency planning start well before document requests ever arrive. Through active planning, in-house and outside attorneys can coordinate to reduce the crush of activity that accompanies the arrival of initial document requests. In almost every patent case, there are activities you can begin prior to the start of discovery to prepare for anticipated document collection. For instance, creating a list of key terms, creating a patent and critical event history, pre‑collecting certain documents and investigating relevant international collection impediments can all be accomplished prior to the arrival of the first document request. Each can serve to set you on the path to a more efficient collection and review effort.

Develop a List of Key Terms

Of all the early collection activities, creation and maintenance of a key term list is perhaps the most crucial. Key terms serve a variety of roles and are important to identify early in the discovery process. They can serve to help identify critical documents during collection and review, to filter large volumes of documents during e‑discovery, and to help train reviewers and outside contract attorneys who have to get up to speed quickly.

On the other hand, failure to identify key terms early can lead to repetitive (and consequently costly) document collection and review down the road. Compounding the problem, re-review of documents can create problems with sequential document production. This occurs when previously non-responsive or unidentified documents are later found and produced long after their familial neighbors were produced. Not only will opposing counsel potentially take issue with this, but it can make later preparation for depositions and trial more time consuming.

Consider developing a master key term list at the very beginning of discovery. This list should be a “living” document shared amongst all litigation and review team members and should be updated regularly as new information is learned. Distributions of dated list copies should be disseminated whenever changes are made. Not only does this apprise team members of new information relevant to collection and review, it can also serve as a reminder to add any new information they may have discovered.

Certain key terms should be identified as early as possible. For example, for marketed products covered by a patent-in-suit, there will frequently be development project nomenclature, such as project name and/or numbers. By identifying that nomenclature early, plus that of any related or precursor projects, it will simplify later collection and review of documents. Similarly, marketed product names and competitive product names are also important terms. Patent numbers, patent application numbers, and patent prosecution docket numbers are additional common terms that should be identified early.

Develop a Patent Family Tree

Also consider developing a patent family tree for all patents-in-suit. This serves not only to identify key terms, but also to give document reviewers and litigation attorneys a quick reference sheet when they are evaluating the significance of a date, docket number, or other prosecution item. A useful patent tree document should include all docket numbers (and any shorthand variations thereof), filing dates, issue dates, continuity claims, inventor names, serial numbers, and, if relevant to assertions of inequitable conduct, prosecuting attorney names.

Develop a Key Event Timeline

By starting a key event timeline early in the discovery process, all team members may easily record knowledge they gain while conducting employee interviews or reviewing documents. A key event timeline can serve as a master record of how the inventive process occurred, testing proceeded, ownership was transferred, and licensing occurred. It is supremely useful for helping to determine conception and reduction-to-practice dates, and for evaluating asserted prior art. A key event timeline should have, at a minimum, a date field, an event description field, and an evidence identification field (e.g., a document Bates number, an interview summary, or some other source identifier for the event described).

Pre-Collect Documents

It is not necessary to wait until the start of formal discovery to collect documents. There are some documents that are almost always requested through initial document requests, or are otherwise useful for investigating the facts of the case. Good candidates for pre-collection include:

  • Invention records and assignments
  • Internal patent docket files
  • USPTO certified patent file histories
  • Current and historical document retention and destruction policies
  • Current and historical organizational charts
  • Contractual agreements involving the patented product, including development, testing, sales, supply, licensing, and assignment
  • Patented product sales and profit/loss summaries

International Collection Preparation

Finally, during the early collection activity period, it is important to identify whether documents and e-discovery must be collected from international locations. If international collections are required, you should determine as early as practical the applicable discovery and privilege rules for those countries.

As an example, e-discovery in Europe is much less common than in the U.S. and is much more restrictive. Throughout much of Europe, employees have an expectation of privacy relating to personal use of their company computer. Therefore waivers may have to be obtained from each employee from whom e-discovery is sought. Further, each employee may have the right to review all data collected from their electronic devices. This can be a time-consuming and expensive process and thus should factor into early negotiations with opposing counsel and decisions surrounding discovery scope.

Agreements with Opposing Counsel

Prior to the formal start of document collection and e-discovery, or during its very earliest stages, it is important to consider reaching stipulated agreements on certain areas of discovery. Limiting scope and defining production expectations early can lead to higher efficiencies and lower costs during later collection and review.


The scope of document collection is acutely important in the current age of e‑discovery. Barring local discovery rules or general orders governing patent litigation e-discovery, there are certain issues ripe for stipulated discovery agreements that can minimize collection and review time.

First, consider a scheduled exchange of filter terms. Filter terms are key words used to identify potentially responsive electronic documents from raw sources such as cloned hard drives, network shares, email servers, etc. Remember that master key term list discussed earlier? This is a good time to trim that list down to the fewest and the narrowest terms that can be used to identify responsive documents. If you have not put significant effort into developing an accurate key term list early in the process, you are in danger of having to perform multiple, expensive iterations of document filtering and re-review. Plus, you may have to disclose revised filter term lists to opposing counsel, thereby shining a light on any newly added terms.

While a filter term list cannot remove your obligation to produce responsive documents, it can set the basis for culling much of the chaff from the review. Consequently, the list should be scrubbed of generic terms and should make significant use of Boolean terms (e.g., “<inventor name> AND <project number>”). If possible, it should also be run through a pre-screening program on a subset of collected documents in order to determine which filter terms are generating too many false positives.

Second, consider agreeing to forgo collection from PDA devices such as mobile phones, tablet computers, etc. PDA e-discovery is an expensive process and, for most patent litigation cases, it is only a productive effort when there is specific evidence contained in unique documents or information that are located only on PDA(s) and nowhere else.

Likewise, consider agreeing to forgo collection from archived backup data. Absent specific evidence of unique documents or information that are not otherwise obtainable, retrieving, filtering, and reviewing archived data is generally more burdensome on the document producer than it is beneficial to the document requestor. Exceptions to PDA and archive document collection can be written into any stipulation, but consider starting with the initial anticipation that no documents will be collected unless specific cause requires such collection.

Finally, consider agreeing to the production of summarized data in lieu of raw documents for certain types of requests. This is, of course, tempered with the caveat that the underlying data or certain specific categories of those documents will be produced upon request.

Summary productions are particularly useful when secondary considerations of non-obviousness are argued. These secondary consideration assertions tend to open the flood gates to subsequent document requests that are directed to broad swaths of marketing, sales, and financial information relating to the commercial success of a patented product. Unfortunately, there is no simple way to electronically filter and distill marketing and sales data. Plus, many documents that contain such data also may contain highly-confidential data for other products that are irrelevant to the case. This can lead to time-intensive redaction efforts, and those efforts are never 100% accurate or effective. Consequently, an early agreement to produce sales and profit/loss summaries (such as the ones you collected/generated in your early collection activities) in lieu of raw responsive documents can save substantial costs during e-discovery. Similarly, agreed stipulations regarding the production of summaries or exemplary documents concerning ancillary test data, market research, promotional efforts, organizational charts, etc. can markedly decrease the time required for document review and redaction.


Document production formats and scope are sometimes not considered until after collection and review has begun. However, if you are able to reach consensus early in the process, it can help guide future collection and review activities. At a minimum, you should identify what, if any, of the following data will accompany a document production:

  • Document custodian data (e.g., who/where it was collected from)
  • Document metadata (e.g., date created, date modified, author, etc.)
  • Red-lining history (e.g., Microsoft® Word’s document review tracking feature)

Further, an agreement should be reached on each party’s preferred document production format. Some questions to consider include:

  • What is the image format – TIFF, PDF, or some other format?
  • How are spreadsheets reproduced?
  • Who has responsibility for OCR – the producing or receiving party?
  • What format will the OCR be in – e.g., will it be paginated?
  • What type of load file is acceptable?

Production of native files is another issue that should be decided early. This can have a significant impact on review time and on redaction efforts. Some questions to consider:

  • Will native files be produced?
  • If so, will all natives be produced or just on demand?
  • Will certain file types, such as spreadsheets, always be produced in native format?
  • How will redactions be handled for documents that are produced in native format?


In conclusion, by carefully planning and implementing early collection activities and agreements with opposing counsel, much of the burden and cost associated with the overall discovery process may be reduced. By proceeding carefully and thoughtfully early in the discovery process, Counsel may reap many benefits at later stages of litigation.

© 2012 McDonnell Boehnen Hulbert & Berghoff LLP

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