1. A computer program product for processing units of work to process in a computing system, wherein each unit of work is comprised of a plurality of sub-units of work, wherein the computer program product comprises a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor to cause operations, the operations comprising: maintaining a plurality of work unit queues, wherein each of the work unit queues are associated with different work unit attribute values that are associated with units of work, wherein a plurality of the work unit queues include records for units of work to process having work unit attribute values associated with the work unit attribute values of the work unit queues; maintaining a plurality of work sub-unit queues, wherein each of the work sub-unit queues are associated with different work sub-unit attribute values that are associated with sub-units of work; adding records for work sub-units of a unit of work to the work sub-unit queues in response to processing the unit of work from one of the work unit queues; and selecting the records for the work sub-units from the work sub-unit queues to process the sub-unit of work.