Intoday’sdynamicbusinessenvironment,ITdepartmentsareunderpermanentpressuretomeettwodivergentrequirements:toreducecostsandtosupportbusinessagilitywithhigherflexibilityandresponsivenessoftheITinfrastructure.GridandCloudComputingenableanewapproachtowardsIT.Theyenableincreasedscalabilityand