Email would probably be most convenient, but a phone number and office should be provided where appropriate. Each member should know the strengths and weaknesses of all members so that questions and problems can be referred to the best member. With this set-up, alumni can take part in advising even if they do not live on or near campus. It is important that team members not only work well together but learn from each other and their advisees. Graduate students and faculty can update members on research.
Alumni bring knowledge of the workplace.
Each member sees a different aspect of the curriculum. If handled properly, an advising team can help break down some of the walls that exist between the represented groups. To paraphrase the Talmud, a wise person can learn from anyone. Team meetings should be designed to reflect this. A possible way to do this is to have a different member teach something at each meeting.