Structure is a fundamental and sometimes intangible notion covering the recognition, observation, nature, and stability of patterns and relationships of entities (Wikipedia). In the realm of business or social organizations, the structure of an organization is derived from the established relationships of 4 key systems in an organization, namely, management, client, finance and administrative.
The structure of an organization is not a static pattern; It is always open to change, actually.
Whatever the kind of relationships exist between the systems, the structure follows. When the relationships of the systems in an organization change, the structure of the organization changes accordingly. It is therefore important to design, or evaluate, the structure of an organization based on the status of the relationships of the systems in the organization. An illustration detailing the supposed structure of an organization may not necessarily represent the true structure of the organization. It is not always the case that the supposedly superior position in an organization is actually the position in authority over the supposedly lower ranked position/s; it could be otherwise.
More than just detailing the hierarchy or the rank of positions in an organization, the structure of an organization should be the true representation also of the actual accountability and power-relationships of the different entities or positions in the organization.