 The team should be as small as possible consistent with their having relevant skills and experience A minimum team size of 4-5  is recommended.In a large process there will be many HAZOP meetings and the individuals within the team may change as different specialists are required and deputies are required for the various roles.As many as 20 individuals may be involved but is recommended that the team should not exceed 7-8 at any time (a larger team will make slower progress adding considerably to the costs).