Data processing in modern information systems often require access to data stored in multiple heterogeneous databases. Schema integration is an important step for providing database integration and interoperability of distributed database systems. The process of schema integration requires knowledge of the semantics of component database schemas and must be supported by a database designer. The paper presents various models containing data versions and time components used in business systems and their possible semantic heterogeneity. Also, the techniques for integration of schemas containing version models are discussed and the methodology for creating an integrated schema with versions is proposed.