To provide the right (required) number of the right (qualified) personnel at the right (specified) time at the minimum cost is the goal for any workforce planning, or military training more specifically system. This paper gives an outline of the areas of Operational Research where the work in the defence domain has been successful and it brings out the role it can play in decision making. This paper looks into the strategies and developments made in Military, Navy and Air Force using operations research since World War II where it was first used to enhance the effectiveness of weapons and other limited resources available.