1. A method for performing systems management on IT-resources using web services, wherein said resources are managed in a computational network within a plurality of runtime environments having different respective instrumentations, wherein a resource configuration database is provided for storing a collection of resource-specific data on said IT-resources, comprising by the steps of: at runtime of a systems management operation directed to a predetermined IT-resource, using a stateless, first generic web service for requesting, in a first request on behalf of a systems management application client, descriptive information concerning said IT resource from respective entries of said configuration database, wherein said descriptive information includes an enumeration of a plurality of different resource types used within said computational network, said predetermined resource belonging to at least one of said plurality of different resource types, said first generic web service for requesting descriptive information concerning any of said plurality of different resource types; selecting a specific one of said resource types corresponding to said predetermined IT-resource from a response of said first generic web service; using a second generic web service for requesting, in a second request on behalf of said systems management application client, meta data describing a plurality of different resource instances currently existing in the network for said selected resource type, said second generic web service for requesting meta data describing any of said plurality of different resource instances existing in the network for said selected resource type; selecting a specific one of said plurality of different resource instances from a response of said second generic web service, the selected resource instance corresponding to said predetermined IT-resource; using said second generic web service for requesting, in a third request on behalf of said systems management application client, meta data describing at least one of: (a) one or more properties of said selected resource instance, and (b) one or more operations currently validly operable at said selected resource instance; and using said meta data describing at least one of: (a) one or more properties of said selected resource instance, and (b) one or more operations currently validly operable at said selected resource instance received responsive to said third request to perform at least one of a systems management operation on said selected resource instance and an access to said selected resource instance, wherein said at least one of a systems management operation on said selected resource instance and an access to said selected resource instance are performed by said system management application client without using said first or second generic web service.