One of the essential tasks of an ATIA is to ‘scope impacts’ or decide what impacts are most
important, thus warran ting more detailed study or special attention from project management.
There is now wide recognition that this activity is more important than the choice of impact
assessment technique used (checklists, simulation models, networks). Six helpful impact criteria
have been suggested by Ahamad and Sammy (1985) to assist with the scoping exercise: