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Establish the team goal: By articulating the dimensions of the decision, including its importance, a manager can reduce ambiguity and help group members focus their analysis, discussions, and deliberations. A clear statement of the question to be resolved can help unify the group and create cohesion that engages members and improves collaboration.
Facilitate a working environment: After the decision goal is established, the working environment must allow for meaningful, honest, and open communication among group members. The manager can help establish norms about how members will interact with each other to foster constructive discourse.
Set clear expectations and responsibility: By setting expectations, managers help team members understand their decision tasks and parameters (for example, deadlines). Managers might assign roles to help structure the decision process, establish a sense of accountability for parts of the group's work, and clarify responsibilities.
Source: Boundless. “The Manager's Role in Group Decisions.” Boundless Management. Boundless, 21 Jul. 2015. Retrieved 13 Jan. 2016 from https://www.boundless.com/management/textbooks/boundless-management-textbook/decision-making-10/managing-group-decision-making-81/the-manager-s-role-in-group-decisions-389-7291/ Please let me know if you need any clarification. I'm always happy to answer your questions.