As the nature of designing becomes more complex, the need for sophisticated methods for storing and accessing design data becomes greater. Requirements for design data storage and retrieval are typically more complex than those for other types of database management systems. Current research in this field includes development of data models for specific design applications and data exchange standards across design disciplines and product life cycle stages (e.g., the ISO STEP standards and the International Alliance for Interoperability, producing standards for the AEC industry).