The purpose of an organizational structure is to clearly define roles and responsibilities (Sullivan, n.d.). A well-defined organizational structure makes the employees and the managers aware of their roles and responsibilities regarding completion of the missions. Let us now discuss three primary project management organizational structures in order to get a better understanding of the situations in which each of these structures serves best to manage the project teams.The functional organizational structure is the most commonly used form of structures in which the decision-making authority remains at the top management level and the projects are assigned to the functional units based on the types of the projects. In functional organizational structure, there is the strong concept of subordination and the focus of the management is towards jobs. The function-based jobs, which are similar in nature, are grouped together in such a way that they form a separate department. In functional organizational structure, the employees of each department have the unique set of roles and responsibilities, which make their duties different from the employees of other departments. For example, the employees of the human resource department perform the tasks of hiring and training, whereas the employees belonging to the operations department deal with different types of business operations, activities, and functions. Some of the main characteristics of the functional organizational structure include a well-defined chain of command, formation of separate departments, strong concept of subordination, centralized decision-making, concentrated leadership, professional similarities between the employees belonging to any specific department, well-defined progress path for the employees, and clearly defined roles and responsibilities.