One step (hopefully in right direction): Redraw the schematic in this way:
1: Change the wires from the AND gate to all flipflops Q output.
2: Make it a inverted OR gate.
Personally I think it's way more difficult to dela with extra inverted outputs. This way the circuit will do the same.
Where did you get that circuit from? For me it looks like the bit order must follow a rule to get the output to change. But I have no clue what to use this for. Maybe to check some phase, but that's just wild guess.
interresting circuit by the way. Mee too wonder if it can be applied to some application.