Decide, Announce, Defend (DAD) is a top-down, minimally participatory method of public management.
Problems and Purpose
The DAD method is often used in response to emergency situations, since decisions are generated through a hierarchy and do not require consensus. In general, the top of this chain of command is occupied by a group of experts who base their decision on scientific or technical analysis. For this reason, the EU's 'Action plan on Science in Society related issues in Epidemics and Total pandemics' (ASSET) recommends that DAD is not suited to situations:
- "Where a wide range of technical, social, cultural and economic factors are influencing the current situation and the various possible alternatives to it
- Where successful implementation involves a lot of people
- Where these people are not in an obvious command structure, but can choose whether to cooperate" 
Origins and Development
While it is difficult to date the origins of the DAD method, The International Atomic Energy Agency gives several examples of public resistance to its use in relation to nuclear waste disposal. It would appear that DAD was used to determine the location of waste sites beginning in the 1980s. It is likely that DAD was used before this (possibly in other areas of public management) but the examples given by the IAEA demonstrate the public push-back that can result from such a top-down decision making process. 
Participant Recruitment and Selection
How it Works: Process, Interaction, and Decision-Making
Influence, Outcomes, and Effects
Analysis and Lessons Learned
The DAD approach is problematic for several reasons. As ASSET points out, "in some contexts – traffic congestion, water supply, domestic energy use, waste reduction, renewable generation, flood risk management – the DAD approach is guaranteed to generate resistance to even the best ideas. Resistance eats up time and resources because it needs a response. The time spent overcoming resistance and defending the solutions against opponents often delays implementation and can lead to the plans being abandoned."  In these cases it is recommended that a process of broad participatory decision-making and consultation of affected individuals be pursued. This avoids DAD becoming 'DADA' or "Decide-Announce-Defend-Abandon."
During a Lecture for the Universiti Teknologi Malaysia, Richard Susskind suggests the "collaborative, adapitve, and management" (CAM) process as an alternative process to the DAD approach. According to Susskind, "collaborative means active involvement and transparency of all stakeholders or those affected by a particular development project. Adaptive is necessary when there is scepticism or difficulty arising from a particular project. Implementation in stages is better so that the parties responsible will have an in-depth understanding and will make improvements continuously. The management aspect needs to take the collaborative and adaptive approach. This means that improvement of the management system should be done in a collective and transparent way, with concerted effort of all parties." 
 ASSET. "Decide announce defend (DAD)," Action plan on Science in Society related issues in Epidemics and Total pandemics. http://www.asset-scienceinsociety.eu/pages/decide-announce-defend-dad
 Richardson, Phil. "A brief history of stakeholder engagement in relation to radioactive waste disposal programmes," International Atomic Energy Agency. https://www.iaea.org/OurWork/ST/NE/NEFW/WTS-Networks/DISPONET/disponetfi... [broken link]
 Susskind, Richard. "New tools for democratic decision making," UTM Premier Lecture Series. http://news.utm.my/2012/05/utm-premier-lecture-series-by-professor-sussk...
The D.A.D. Model of Stakeholder Engagement - Decide, Announce and Defend:
The Deliberative Practitioner: Encouraging Participatory Planning Processes: https://books.google.ca/books?id=ywJXreTLoBcC&pg=PA63&lpg=PA63&dq=decide...
Stakeholder Involvement Throughout the Life Cycle of Nuclear Facilities: https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1520_web.pdf
Beyond Decide-Announce-Defend (DAD) and Not-in-My-Backyard (NIMBY) models? Addressing the social and public acceptance of electric transmission lines in Germany