A flat organization (also known as horizontal organization or flat hierarchy) is an organizational structure with few or no levels of middle management between staff and executives. An organizational structure refers to the nature of the distribution of the units and positions within it, and also to the nature of the relationships among those units and positions.[1] Tall and flat organizations differ based on how many levels of management are present in the organization and how much control managers are endowed with.[1]
Transforming a highly hierarchical organization into a flat organization is known as delayering.