An exemplary embodiment is a method for creating and identifying different kinds of groups of cooperating system images within a single machine, a single central processor complex (CPC) where each kind of group has a different functional purpose. Such a collection of cooperating system images is referred to as a logical partition cluster (LPC). An LPC is created or identified using a diagnose instruction. The diagnose instruction includes a subcode field designating a function to be performed and a logical partition cluster type field indicating the type of logical partition cluster said function is to be performed on.