Public participation in choices involving industrial risks may enrich the choice in many ways, but it also results in more complex, if not messy, decision making. The purpose of this chapter is to offer a general framework to account for the decision-making processes that unfold over time in connection with an industrial project and to situate public participation within these processes. I build on the “garbage can model” of decision-making, a famous and provocative conceptualization that has generated a thread of research in organization studies and political science. Decision making is understood as resulting from the encounters of problems and solutions supported by a number of participants with varying degrees of involvement in the decision. The encounters are regulated by organizational arrangements that filter the flow of participants, problems and solutions. What constitutes a good or bad regulation is discussed in the conclusion.