A CD-3A, or CD-3B, etc., phase may be needed for long-lead item procurement.

While there is potential risk in procuring equipment before the design is complete, the potential schedule improvement may be significant and more than compensate for the risk. Procurement of vendor engineering designs, for example, greatly reduces the risk of incomplete or incorrect final designs that would otherwise require rework and potentially impact cost and schedule. Other examples include procurement of materials and major sub-systems that are independent of remaining design uncertainties, and early procurement retires significant risk in both cost and schedule.

The need to phase CD-3 should not be confused with minor, early activities that are necessary and generally performed prior to CD-3. Activities such as site preparation work, site characterization, limited access, and safety and security issues (i.e., fences) are often necessary prior to CD-3, and may be pursued as long as project documents such as a Project Data Sheet (PDS) requesting construction or Project Engineering Design (PED) funds to procure the long-lead items and funding approvals are in place.

If CD-3A is anticipated, the need for this decision and the process should be documented in the PEP or Tailoring Strategy.

Note: On January 13, 2021, DOE Office of Science issued memorandum on instituting Supply Chain Analysis reporting requirement of Order 413.3b projects. Policy expected to be released on May 1, 2021.