Lay out all the processes in the Mixed Model PFD workstation by workstation. It is a good practice to start at the end of the line and work your way upstream through the path of highest volume. Ignore all physical layout constraints such as floor space or walls. Once the path of highest volume is laid out, begin to lay out the feeder processes, rework loops, and independent processes.
Determine if each process will be done sequentially, like an assembly line, or in parallel, with each station completing all of the work steps.