#TEAP1311DW12
I would go with parallel approach although there is not much risk in it
because i assume the cost would be alot less because its online.
At first i woukd pick the right software
secondly would arrange best people for it even if the screw up so they dont do that much damage
thirdly i would take the risk and submit all of it trusting the new system
but ofcourse i still have the old system
then if it fails iw oulkd kjust run both