Unloading a model removes all versions of the model. You need to unload a business measures model only when you no longer want any of the model versions, which means you are not working on the processes of this model any more.
Unloading a business measures model will purge the model from the execution engine as well as delete the model information from the repository database. You can choose to keep the model data for reporting. This will lead only to purge the model from the execution engine and to keep the model's information in the Repository database to allow the model's data to be viewed in the dashboards.
Once a model has been completely unloaded, the database tables that was created for this model and its contents of model execution data will remain without deletion. These database tables should be dropped and the replication artifacts should be removed. It is the responsibility of the database administrator to drop or archive these database tables
Follow these steps to unload (delete) a business measures model that has been previously imported to the WebSphere® Business Monitor.