"Rational Decision-Making" is a management topic that argues about decision-making in determined and scientific process especially by "Operation Research". However, using operation research models in public sector has its typical Proponent and an opponent. Moreover, Iran is one the most five countries that has conducted scientific studies about operation research. The study had analyzed twenty-nine case studies reporting different operation research techniques in different governments. The result claims that operation research models have two aspects of managerial effects: Efficiency and Effectiveness. They are efficient in managing public technologies and tools (like distributions technologies etc.) but their effectiveness on public administration is dubious. Studying these kinds of case studies is appealing and practical for researchers to have a sounder view of the role that operation researches play in public issues.