FAB 3000 - Hierarchy Concepts:
Fab3000 is one of the only CAM software tools that can natively implement gerber data in a hierarchal fashion. Initially this concept of using hierarchy with Gerber files can seem confusing, but give this "Quick-Start" a chance and hopefully everything will become clearer.
Essentially Fab3000 consists of two hierarchal resources: Job, and Insert:
Job - A single design (i.e. PCB) with its own unique layers, dcodes, and other attributes. (All data imported and 90% of editing are handled at the Job level). Note: In ODB++ terms, a Step is the same thing as a Job (in Fab3000)
Insert - An insert represents the inclusion of one job as a part of another. The job containing the insert is the parent job, and the job that is inserted into the parent is the child job. Using this parent/child relationship, you can continue the hierarchy for as many levels as needed to express a complete design.