The best choice for your organization depends upon how many people use the product, how often they require access, and how you prefer to purchase software.
An IBM Rational Authorized User license authorizes an individual to use a Rational software product. You must obtain an Authorized User license for each individual user who accesses the product in any manner. An Authorized User license cannot be reassigned unless you replace the original assignee on a long-term or permanent basis.
An IBM Rational Floating license is a license for a single software product that can be shared among multiple team members; however, the total number of concurrent users cannot exceed the number of floating licenses you purchase. For example, if you purchase one floating license for a Rational software product, any user in your organization can use the product at any given time. Another person who wants to access the product must wait until the current user logs off.
To use floating licenses, you must obtain floating license keys and install them on a Rational License Server. The server responds to user requests for access to the license keys; the server grants access to the number of concurrent users that equals the number of licenses the organization purchased.
The token-based license model means that you can buy a certain number of token licenses. If you use a Rational tool that checks out a feature that is token-based, the feature line in the license file specifies the number of tokens that are checked out. Token-based licenses can only be used with floating licenses. They cannot be used for authorized user license. For more details about token licensing, contact your local IBM marketing representative.
Processor value unit (PVU) licensing is for providing you pricing structures that are responsive to both the type and number of processors that are available to installed products.
Entitlements can be full capacity or subcapacity. Under the processor value unit licensing structure, you license software based on the number of value units assigned to each processor core. For example, processor type A is assigned 80 value units and processor type B is assigned 100 value units. If you license a product to run on two type A processors, you must acquire an entitlement for 160 value units. If the product is to run on two type B processors, the required entitlement is 200 value units.
The processor value units table, which assigns a number of value units to each supported processor type, is regularly updated to provide for the introduction of new processor technologies. Agents retrieve information about the number and type of processor on the monitored computer or partition and the table is used to determine the level of license use in terms of processor value units.
For more information about managing licenses for your Rational product, see the IBM License Metric Tool Knowledge Center to learn about processor value unit licensing at http://www.ibm.com/support/knowledgecenter/SS8JFY_9.0.0/com.ibm.lmt.doc_9.0/com.ibm.license.mgmt.doc/overview/c_processor_value_unit_licenses.html