Performance periods are available for work that has variable resource requirements and for which your goals change as the work uses more resources. You specify a goal, an importance, and a duration for a performance period. Duration is the amount of service that period should consume before going on the next goal. Duration is specified in service units. For more information about defining durations, see Defining service coefficients and options.
You can define multiple performance periods for work in subsystems which use address spaces or enclaves to represent individual work requests. For a list of subsystems for which you can specify multiple periods, see Subsystem support for goal types and multiple periods.
Multiple periods are not supported for work in the IMS™ and CICS® subsystem work environments because service units are accumulated to the address space, not the individual transactions. So, the system cannot track a duration for those transactions.Multiple periods are also not supported for work in the SYSH subsystem.