Researchers at the National Institute of Standards and Technology are developing a virtual manufacturing cell. This cell will contain simulation models of a wide range of manufacturing equipment, processes, and systems. It will have commercial and prototype applications software which implement production funtions from order release to final inspection. There will be an information base and a collection of interfaces which will provide the integrating infrastructure for these applications. These interfaces will be based on information models and exchange protocols, and will specify what information is shared across those applications and how it is exchanged. This paper describes the current virtual manufacturing cell, with special emphasis on the hierarchy we are developing to control activities within the cell.