One aspect of teams that can set them apart from other groups is their level of autonomy. Hackman developed a hierarchical model of team autonomy which consists of four levels of team self-management. It is imagined along a continuum, starting with a manager-led team in which team members complete the required tasks but someone outside the team performs the executive functions. Next in the hierarchy are self-managing teams, followed by self-designing teams. Finally, at the top of the hierarchy, come self-governing teams. The model describes four different types of control that fully self-governing teams can possess. These include control over the execution of the task, monitoring and managing work processes, control over the design and performance of a team, and setting the overall direction of the team.