1. A computerized method for processing work items of a workflow system, said method comprising: retrieving, by a processor of a computer system, information identifying work items from a server responsible for handling work items based on a set of configuration rules; said processor storing the information in a cache that comprises N containers; said processor searching for matching work items in the cache in response to a work item request from an application, said work item request specifying n+1 criteria for work items such that n+1 is at least 2, wherein N is a product over a cardinality C i of criterion i from i=0 through i=n, wherein C 0 =1, and wherein C i is at least 2 for i=1 through i=n; said processor delivering, in response to finding at least one work item matching the work item request, a piece of information identifying to the application the at least one matching work item from the cache; and said processor storing information identifying work items of an allowable type of work item of a set of allowable types of work items in a respective container of the N containers.