Workload management of stateful program entities

In a workload managed system comprising a plurality of server processes each capable of supporting a given program entity, such as an Enterprise JavaBeans™ specified stateful session bean, a stateful session bean instance is passivated, by writing it to a bean store, on completion of a unit of work. On next use the session bean is reactivated, by reading it from the bean store, in any one of the plurality of servers thereby allowing workload management for stateful session beans. A routing table is maintained, in non-volatile mass storage, that contains location information for units of work and stateful session bean instances, used to maintain unit of work-server affinity for the lifetime of the unit of work Stateful session beans instances are associated with ID keys that include a flag that is used to indicate whether or not the routing table contains location information for the bean instance.