Chassis schematic

Power distribution.
Interface  to CPUs (ethernet, VGA, Serial port, keyboard, mouse)

Chassis design ( ? + a few suggestions from GTP)

I provide:

Coordinates of parts on the edge of the board
Coordinates of mounting holes on the testboard

Someone Else provides:

Rack mount chassis concept... Height, connector placement etc

Chassis component specification... PS, brackets, spacers, indicator lamps, switches etc.

Wiring harness...  Interconnects to power supply(s) and various other components

Internal component layout

Internal power supply placement
power connector and fuse
ventelation fan

Chassis fabrication

Turn the chassis design into stamped, punched and drilled

Chassis wiring and system integration

Pretest CPUs. Assign network ID. Preload software.
Assign each testboard its own bus address.
Attach mounting hardware to each board
Attach wiring harness to test boads.
Stack test boards boards together.
Stack the CPU on the stack of test boards  (Good time to pretest with CPU)
Mount the stack of boards in the chassis
Attach stack to power supplies

Subsystem testing

Exercise the CPU with test boards.
Demonstrate signal acquisition from each board.
Documentation of test results.

Pack completed subsystems for shipment to the  south pole