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 at least on a set of configuration rules; said processor storing said information in a cache; said processor searching for matching work items in said cache in response to a work item request from an application, said work item request specifying at least one criterion for said work items; said processor delivering, in response to finding at least one work item matching said work item request, a piece of information identifying said at least one matching work item from said cache to said application; said processor maintaining statistics on said work item request; and said processor modifying said set of configuration rules according to said statistics; said method further comprising providing a set of allowable types of work items, wherein said work item request indicates a type of the requested work item, wherein said cache comprises a plurality of containers, and wherein said method further comprises storing said information identifying work items of one of said allowable types in a respective container; wherein said providing the set of allowable types of work items comprises providing n+1 criteria such that n is at least 2 and further providing a cardinality C i of criterion i for all integer values i from i=0 through i=n, wherein C o =l, wherein C i is at least 2 for i=1 through i=n, wherein each allowable type of work item is a unique combination of one value of each C i , from i=0 through i=n, and wherein the plurality of containers consist of N containers such that N is a product over C i , from i=0 through i=n.