Site problems Test Development Strategy (TDS) The TDS should guide efforts through the Technology Development (TD) Phase within the established cost goals. The TD Phase may be planned to include the System Requirements Review (SRR), System Functional Review (SFR),  and Preliminary Design Review (PDR), which begs a level of maturity in a capabilities document, specifically a Capability Development Document (CDD). The CDD is a Milestone B requirement, so program or project offices planning a PDR in the TD Phase need to work closely with the requirements and capabilities communities to integrate development schedules. The TD Phase begins based on the Analysis of Alternatives (AoA) results and an Initial Capabilities Document (ICD) that may be at a very high level. If a full SRR and SFR activities are planned in the TD Phase, they should depend on a stable, draft CDD or run the risk of not having traceable lower-level requirements at the PDR. The TDS should ensure appropriate efforts are undertaken to meet the statutory Milestone B certification criteria as well as regulatory requirements for entry into the Engineering and Manufacturing Development (EMD) phase. Final Requests for Proposals (RFP) for a TD Phase cannot be released, nor any action be taken that would commit the pre-program to a particular contracting strategy, until the Milestone Decision Authority  (MDA) has approved the TDS.  Defense Acquisition Guide