This 2011 UNDAC Review is the second review of the UNDAC system to be undertaken since its creation in 1993 and follows a first review carried out in 2001. It is the result of a long and highly consultative process aimed at analysing the effectiveness, efficiency and impact of the UNDAC system today as well as its readiness to meet future humanitarian challenges. The Review has provided the opportunity to re-explore the position which UNDAC occupies within OCHA as the only tool to link the international humanitarian response system with the wide variety of disaster management actors not normally involved in international humanitarian coordination processes. The findings of this 2011 Review confirm that while new initiatives and changing priorities might have distracted attention away from this long-established mechanism, the UNDAC role remains both valid and effective. The UNDAC system allows OCHA to rapidly deploy a team of trained experts with local knowledge and technical resources to assist affected governments and the international humanitarian response system with strengthened capacity in coordination, information management and assessment in sudden-onset emergencies. While the wide range of skillsets available to OCHA from amongst the 250+ active UNDAC members enables diverse and specific needs to be met, the “team” approach gives the flexibility in terms of size and composition which allows UNDAC teams to meet the requirements of any given situation. The high regard that stakeholders have for the UNDAC concept and its core values has been a recurring theme of this review process. Documentary reviews, interviews, surveys and workshops have revealed not only the great depth of interest in and commitment to the UNDAC system, but also the high level of attachment and pride felt for what UNDAC has come to represent across its broader network. Nonetheless, UNDAC members and wider stakeholders have shown no complacency towards the UNDAC system and have engaged fully and constructively in this review process. The nine main findings of this 2011 Review reveal that, while the UNDAC concept remains valid and bridges a critical gap between disaster management and humanitarian response coordination, it is largely the processes through which the UNDAC system is delivered which require improvement. The nine corresponding sets of recommendations seek not only to reinforce the strengths of the UNDAC concept but also to enhance its delivery, both in terms of disaster management and international humanitarian response, in support of OCHA’s mandated role in emergency response and preparedness for response. In recent years, a vast array of new emergency response tools, partnerships and initiatives have been developed in the international humanitarian response system, which – whilst welcome – remain nonetheless “bewildering for an RC/HC”. In this environment, the UNDAC system is broadly recognised as being able to supply, upon request, a rapidly-deployable set of resources to provide significant support to both a UN RC/HC and a host government in an emergency situation. UNDAC’s role is to get coordinated response mechanisms moving in the first, critical stages of the emergency and to support the RC/HC through establishment of the whole response “platform”, including assessment coordination and pre-cluster coordination, before longer-term OCHA surge staff step in and take it forward. The UNDAC system is thus an integral part of OCHA’s response capacity; it is also the only response tool which deploys integrated teams with adaptable skillsets.