1. A computer system for modeling the structure of an enterprise comprising a first class of objects, an object of said class representing an organizational unit of the enterprise, said class comprising a method for assigning and/or deassigning to an object of said class at least one attribute from at least five types of attributes comprising: a first type describing a work to be performed by the unit; a second type describing a legal entity, which said unit represents; a third type describing a disciplinary or line management properties of the unit; a fourth type describing a financial responsibility of the unit; and a fifth type describing a location, which said unit represents; the system further comprising means for assigning and/or deassigning to an object of said class at least one property depending on the assigned attribute.