Abstract Processes for decision making by large groups such as professional associations have not adapted rapidly to the growing complexity of the situations those associations face. This paper describes a ten-step procedure which has enabled professional bodies to engage a large sample of their constituency in extensive planning exercises. These planning workshops addressed a wide range of complex issues, many of which were sensitive and threatening. The steps comprised identifying the problems, collating the agenda, analysis of the issues raised, deriving a structured sequence of tasks, pre-circulating papers, forming working groups, providing adequate time and facilities in a suitable setting for effective workshop activity, ensuring communication among groups within the workshop, managing the plenary reporting and consensus seeking, plus recording and circulating the report back to members. Groups worked cooperatively and constructively without evidence of intragroup competition, which reflects both the homogeneity of purpose within those professions and the effect of strong task structuring.