This paper discusses the concept of cyber defence exercises -CDX- that are very important tool when it comes to enhancing the safety awareness of cyberspace, testing an organization's ability to put up resistance and respond to different cyber events to establish the secure environment, gathering empirical data related to security, and looking at the practical training of experts on this subject. The exercises can give ideas to the decision makers about the precautions in the cybersecurity area and to the officials, institutions, organizations, and staff who are responsible on the cyber tools, techniques, and procedures that can be developed for this field. In the cyber defense exercises, the scenarios that are simulated closest to reality which provides very important contributions by bringing together the necessity of making the best decisions and management capabilities under the cyber crisis by handling stress and coordinated movement as a team. The objective of this paper is to address the issue from a scientific point of view by setting out the stages of planning, implementation, and evaluation of these exercises, taking into account and comparing international firefighting exercises. Another aim of the work is to be able to reveal the necessary processes that are required for all kind of cyber exercises, regardless of the type, although the processes involved vary according to the target mass of the planned exercise.