a method is disclosed for managing the performance of shared computing resources in furtherance of delivering on - demand it services to multiple customers . the inventive method comprises predicting the performance of resources allocated among the customers to minimize performance related problems ; preventing performance related problems by evaluating the impact of changes in resource allocations ; reacting to performance alerts to resolve performance related problems ; and determining the appropriate level of resource performance needed in service level agreements , and that these requirements detailed in the service level agreements are achieved . this performance management method ensures that the demands of the customers are not affected by the allocation and utilization of the shared it resources .