In theory, the continuity rules would be derived from the definition of the enterprise (or other units) and its statistical uses. In principle, the continuity of an enterprise depends on the continuity of its production factors: employment, machines and equipment, land, buildings, management, and intangible assets. The continuity of these factors can be measured and weighted to decide upon the continuity of the enterprise. In practice, the continuity rules consider three main criteria: continuity of control, economic activity and location.