Each Endevor processor group is defined under a particular type, and each type is defined under a particular system.
On the other side, each system must have subsystems defined under it, and each element must belong to a system, subsystem and type.
Why is it that types and processor groups are not defined under subsystems instead of systems?
The idea behind the initial Endevor design was that a system represents an application group (for example, Finance) and each subsystem represents a particular application within the group (for example, Accounts Payable).
Endevor types were intended to map the different kinds of items that comprise an application (JCL, COBOL programs, copybooks and so on). These types were initially considered to be shared between all the applications in a particular group. For this reason, each type and its related processor groups are defined under a system and not under a subsystem.
Endevor offers great flexibility so each site may use its own criteria to classify elements. For example, a site may not use the idea of subsystems at all, or maybe each subsystem holds elements of only one type so that not all types and processor groups are used in a particular subsystem.
However, regardless of the particular implementation, since the structure of the MCF files that hold the inventory is designed following the initial Endevor design, this forces to define structures adhering to it: