Crafting a "Mission Statement" for a work group is a pop-business technique that often turns into an exercise in cliche-spewing. But on the other hand, as a wise friend (JC, 15 December 1999) wrote re "the importance of understanding the mission":
I hold the view that a clear and concise mission statement serves to concentrate the mind in times of stress and turmoil. When upper management is clueless, and stuff is happening, one can always ask one's self, "Are my actions accomplishing the mission?" A former colleague exemplified this for me as a result of his service in the Marines as a tank platoon leader. He would ask himself at the end of each day, "Am I better prepared, through fire and maneuver, to close with and destroy the enemy?"
Concise and to the point, albeit a bit violent ... but that was the job. (A tiny quibble: are the words "upper management" and "clueless" redundant? (^_^))