1. A computer system for modeling a context representation in a business application, comprising: a database storing at least one collection of references to a plurality of entities; and a processor executing instructions to: determine a subset of the plurality of entities that are relevant to a current context, the current context comprising a combination of at least a user context and a session context, the user context comprising at least one of a role, project, or personal preference, and the session context comprising at least one of a last action or a manipulated business entity, assign an activation attribute to at least one context entity included in the determined subset, the at least one context entity having a temporal validity, and the activation attribute indicating an importance level of the at least one context entity in the current context, and model the context representation using the activation attribute assigned to the at least one context entity, wherein the modeling comprises using a semantic net data structure comprising nodes and relationships between the nodes, wherein the context representation is modeled to include an entity related to the at least one context entity, and the importance of the related entity is derived from the activation attribute of the at least one context entity referring to the related entity, and the indicated importance is determined in accordance with the sum of the products of the activation attribute values of the referring at least one context entity and a weighting factor assigned to the relation type linking the at least one context entity and the referred entity.