Hope you are doing good….
I have found an Primus article “What is the Navisphere Quality of Service Manager (NQM)?".., I hope it is also applicable to Unisphere as well….
As per the Primus Article it says “Navisphere Quality of Service Manager (NQM) is an optional product. You need to buy it and install the enabler to use it. There is a demo on emc.com NQM and Analyzer are independent products. Analyzer helps you understand what is happening or what has happened on the array in very great detail depending on your level of interest. It is designed to support performance tuning experts and service personnel. NQM works at the LUN level. You can easily arrange LUNs into I/O Classes and measure resource utilization IOPS/bandwidth and the like and then apply policies to control how the array prioritizes server I/Os to meet your needs. For example, NQM can be scheduled to start and ensure that a backup task gets priority over other I/O to make sure it completes within the backup window”