e User inputs of CPW o A clear specification of the academic issues(THE THEORETICAL MODEL Is the problem properly defined? Is the model properly structured? e Are all the variables required specified? e Are the variables of interest properly defined? o Explicit recognition of the package handling facilities(BUILDING A WORKSHEETUser inputs of CPW ⚫ A clear specification of the academic issues (THE THEORETICAL MODEL ) ⚫ Is the problem properly defined? ⚫ Is the model properly structured? ⚫ Are all the variables required specified? ⚫ Are the variables of interest properly defined? ⚫ Explicit recognition of the package handling facilities(BUILDING A WORKSHEET )