The Forming – Storming – Norming – Performing model of group development was first proposed by Bruce Tuckman in 1965, who maintained that these phases are all necessary and inevitable in order for the team to grow, to face up to challenges, to tackle problems, to find solutions, to plan work, and to deliver results. (see the whole Wikipedia article)

• Forming, Storming, Norming, Performing and the roles of the facilitator at each stage
• Leadership activities at each of the development stages