Hamid has selected one middle manager from each department that will be affected by the updated system and one lower-level manager from each department, along with a few senior staff as well as the project sponsor for a JAD session. He is trying to.

Have a broad mix of organizational levels in the JAD session

Explanation:

It is not possible for Hamid to include every employee in the JAD session, what Hamid needed to do is to select participants from the different departments and other key important people to ensure every one is well represented at the JAD session. Selecting lower-level and mid-level managers from the affected departments as well as the some senior staff and the project sponsor for the JAD session will ensure everyone's interest is well represented at the session.