By implementing various types of tags, easy management and control of assets in a business system is enabled. These assets may be virtual machines, hardware assets, personnel assets, etc. System tags are determined and associated with an asset automatically. Virtual tags and dynamic tags are tags that do not contain the information sought—rather, these tags contain instructions about how to determine the tag value associated with an asset. Management tags are user-entered tags indicating information about an asset based on the knowledge of an individual. These tags can be combined using Boolean algebraic operators, resulting in a tag-based algebra system, which enables a Tag-Based Query Language for searching a universe of assets based on the associated tags. Additionally, tag-based algebra enables access control based on tags associated with a user, assets in a universe of assets, and enables policies to be enforced in a universe of assets.