Department of Homeland Security (DHS) Science and Technology Directorate (S&T) delivers solutions with innovative tools, technologies, and knowledge products for the Homeland Security Enterprise and first responder communities to support ongoing operations and dynamically respond to emerging threats.  DHS S&T faces similar challenges to DoD transitions, where (1) technology advances occur faster than acquisition requirements development and (2) widely available commercial technology allows increased adversary access to technology. These challenges combine to make it difficult to maintain a technological advantage.  It cannot be assumed that even well designed R&D solutions will successfully transition to full operational use and positively impact operational metrics.  Rather, this must be explicitly planned, funded and incrementally measured.  Ending S&T involvement in programs at transition can result in solutions that are not fully operationally integrated by the end users and/or are potentially shelved by component leadership without operations and maintenance budget planning or reach back to developers during this critical post transition operational implementation phase.  S&T has recently gone through an organizational revitalization that has prioritized and shifted the view of the life of a program to include a Post Transition phase and is currently piloting Post Transition Performance (PTP) assessments as a systematic approach to not only support operational integration of delivered solutions, but also the planning and execution of assessment for operational impact.  A critical part of the performance assessment process/method includes defining appropriate metrics and sampling at various stages of the R&D program, including project inception (to establish a baseline), mid-program (to assess operational changes that could confound measurement), at transition (to ensure the solution functions as described/intended), and after operational implementation (to assess if the solution did improve operational efficiency and/or effectiveness in the intended operating environment).  The presentation will focus on demonstrating the need for PTP assessments and establishing standard processes.