This paper aims at presenting an interrelation between management or organizational science and policy sciences. Both sciences have developed by influencing and learning with each other. For example, bounded rationality model in management affected policy analysis, while garbage can model developed in policy sciences impacted on management theory. Especially, it is shown that as the new public management (NPM) has emerged in public sector reforms, private sector and public sector management as an implementing part of policy sciences are complementary to improve performance and strengthen accountability.