1. A computer-implemented method for identifying optimal allocations of computing resources in a data processing arrangement having a plurality of computing machines that host a plurality of application processes, comprising: establishing a plurality of server models, each server model including one or more server nodes, wherein each server node has an associated set of capacity attributes; designating a layered relationship between the server models, wherein for a first server-model layer immediately above a second server-model layer, the second server-model layer includes respective models that represent the nodes in the first server-model layer; establishing a plurality of service models, each service model including one or more service nodes, wherein each service node has an associated set of demand attributes; designating a layered relationship between the service models, wherein for a first service-model layer immediately above a second service-model layer, the second service-model layer includes respective models that represent the nodes in the first server-model layer; normalizing the capacity attributes and the demand attributes; and generating an optimized mapping of service nodes in a user-selected service model to server nodes in a user-selected server model as a function of the associated sets of demand and capacity attributes.