How do most teams usually get created and work? One would think that choosing members for new project and product development teams was modeled after the military - the military draft system. Members are usually selected from various departments by their managers based on availability, knowledge and expertise. Sometimes, new members are selected so that they can gain team or project experience. They are almost always a mix who have other duties and objectives.
Due to the process, what’s interesting (and ironic) is that teams usually gain the most cohesiveness and team members really get to know each other personally…at the product or project release celebration – when it’s all over!
It would make a lot more sense to have a team get-together BEFORE the work begins. Have some team building exercises off site, a team lunch/dinner/trip, etc. so that people can gather informally to get to know, understand, and trust each other. It doesn't have to be expensive or formal. Go bowling, play mad-libs...you want the team spirit at the beginning, not just at the end!