A cluster is a collection of computers that can be accessed independently or as a single unit. The cluster can take a single work unit, defined as either an HTTP request or RMI method call, and distribute it to one of many Windchill servers.

The main advantages of a cluster over a single server are increased performance, scalability, and reliability. Performance increases because Windchill server processes have less competition on a given node. The system is scalable. As the load increases, additional Windchill servers can be added. This scalability also provides a more reliable system. When a Windchill server fails, requests can be directed to the remaining servers.