Since the assignments are dependent on information to be collected by others, there will likely be regular revisions of your plans as additional information is brought back to the group. You should not produce a final report until after the last group meeting. In all cases, in addition to explaining what you are going to do, document how and why you are going to do it. Decide roles within group. Decide initial assignments.
Focus groups meet by cases.
Focus groups meet by cases. Continue as above. Exchange information about your respective areas. Use new information to adjust approach to cases. Focus groups meet by cases and finalize plans.