In the event that you are modifying a device to the point where you may need to have software modification, it will need validation. If it is a modification that do not need animal testing but may still require a higher level of safety when in use before the modification it may require just as much work and a class III device when going through the validation. Also, if the device is a combination or my be very unique it may need peek some interest with the FDA and may require a greater deal of explanation. This process can be timely and can be comparable to a class III device.