This article presents PS, a policy simulator tool intended to serve in the validation and performance evaluation of policy-based management solutions. PS is a discrete process-based simulation environment which allows the specification of all major components required for a policy-based management solution. These include the ability to specify management policies, events, metrics, probes, service-level objectives, service-level agreements, as well as business-level objectives. We describe the main components of PS and show how it has been used to evaluate the performance of a policy-based management solution for a Web application hosting SLA