T. James Cass

Manager, Review Services and Senior Counsel


June 17, 2021


Once a dispute has arisen your enterprise will be required to preserve and produce records relevant to the issues in the dispute.  This is referred to as the “Identification” phase of an eDiscovery project.  As part of this phase, you need to identify the location of potentially relevant data.  The identification phase involves understanding the location and nature of the data, and the people involved.  This article will address the location and nature of the data, also referred to as a “Data Map”.


A Data Map is required to maintain appropriate records of the project and will assist in creating a defensible and most efficient preservation and collection plan.


There are many sources of potentially relevant electronically stored information (ESI).  These sources include traditional sources such as project servers, email accounts, local computer drives.  It also can include data from project management software, smart phones and devices, social media and the IoT (Internet of Things, for example your vehicle GPS data, fitness device, video doorbells).


Despite the name, a Data Map is not actually a map, though in some cases a visual representation does assist in mapping out networks, or if data is in multiple locations.  A Data Map is simply a detailed list/spreadsheet of the hardware and software sources of potentially relevant ESI.  It should also identify any record retention schedules and locations of relevant ESI that may be hosted in the cloud or held by a third party (i.e., a subcontractor or bank).


Your Data Map for each source of potentially relevant ESI should include information on:


  • Hardware and operating systems
  • Location of data
    • Geographic source
    • Internal or hosted
  • Software
    • Current or legacy
  • Retention policies

The above list is not exhaustive.  The information will need to be obtained from discussions with persons involved in the enterprises IT systems.  It is critical to have a clear understanding of the source and location of potentially relevant ESI so that it can be properly preserved.  If you do not identify the source and location of the ESI, it cannot be preserved.  A detailed Data Map is also used to confirm that all necessary ESI has been collected.


A Data Map in conjunction with custodian interviews, or interviews with those who created or have access to the data, will allow an enterprise to defensibly identify, preserve and collect the least amount of data while still complying with obligations to produce relevant information.  A well thought out preservation and collection strategy will minimize costs throughout the eDiscovery process.


A comprehensive Data Map will also assist in developing a discovery plan with opposing parties by providing an understanding of what is reasonably available, and as importantly, understanding of what is not reasonably available.  This includes the ability to obtain information and records out of proprietary document management systems and other databases.  Combined with custodian interviews, this information will allow the parties to begin to assess the time and costs associated with preservation and collection of sources of potentially relevant ESI.


It is unlikely that any one person within an enterprise can construct an accurate, comprehensive, and defensible Data Map, and a fulsome Data Map will typically require multiple conversations.  In our experience, employees will work around even the best implemented document management policies, and it is important to supplement the Data Map with custodian interviews to locate all required data.


As with all phases of eDiscovery, keeping good notes that also include rationales for decision-making points is important to maintain continuity, defensibility, and appropriate transfer of knowledge to counsel.


T. James Cass is Manager, Review Services and Senior Counsel at Heuristica Discovery Counsel LLP.  Heuristica has offices in Toronto and Calgary and is the sole national law firm whose practice is limited to eDiscovery and electronic evidence.  Heuristica has considerable experience in investigations and  disputes and recently became the first law firm in the world to be awarded RelativityOne Silver Partner status.