This chapter outlines the process of developing and implementing policy in the security sector. It discusses 7 key issues: 1) importance of human and institutional capacity, 2) policy communication and debate, 3) policy analysis, 4) factors influencing major policy reviews, 5) policy development, 6) implementation, and 7) oversight. It explains why policy is important for providing guidelines, accountability, and predictability. The politics of policy processes are also examined, emphasizing the importance of governance, transparency, human rights, and professional autonomy of security forces. The context of policy development during periods of change or stability is discussed.