Building metrics to decide how and whether moving to IDaaS means considering what variables and strategy have to be taken into account when organizations subscribe identity as a service contracts. Before moving any IdM to the Cloud, organization should balance costs and risks. Accordingly, metrics adopted should be enough flexible to be applied from both a company that is developing an IdM system and a company that already has a IAM in operation but is considering to move the ID to the Cloud. The metric introduced below is included into a coming IDaaS Best Practices helping companies to understand, evaluate and then decide if and how moving ID to the Cloud.