Be sure that the entire project team is able to share their perspective and expertise especially within their span of control.You will find 1 or 2 people on a project team will be much more vocal than others so be sure that you ask those that are not voicing their subject matter expertise.As the Project Manager it is up to you to manage this.You may need to say "let's hear other perspectives from the project team" or something like that.Can you think of any other ways to manage those that are dominating the conversation and encourage those that are not participating?