A method for operating in an emulated environment, the method comprising: generating and outputting , by a plurality of certified, production line replaceable units, LRUs, operating in an operational environment, physical environmental data and production LRU output data; emulating , by a plurality of emulators in an emulation server, the plurality of certified production LRUs; transmitting, by the plurality of certified production LRUs, the physical environmental data and production LRU output data to the plurality of emulators via data diodes; generating and outputting , by the plurality of emulators using the physical environmental data, a model of the operational environment; generating and outputting , by a plurality of pre-certified LRUs using the model of the operational environment, pre-certified LRU output data, wherein the plurality of pre-certified LRUs correspond to the plurality of certified production LRUs; transmitting, by the plurality of pre-certified LRUs, the pre-certified LRU output data to the plurality of emulators; and allowing, by providing data diodes, only one-way transfer of data between the plurality of certified production LRUs and the plurality of emulators such that no data and/or commands can be transmitted to the plurality of certified production LRUs from the plurality of pre-certified LRUs via the plurality of emulators, wherein pre-certified LRUs are LRUs that have not been certified for use on a vehicle, and wherein each certified production LRU of the plurality of certified production LRUs is connected to its respective emulator of the plurality of emulators and each pre-certified LRU of the plurality of pre-certified LRUs is connected to its respective emulator of the plurality of emulators. generating and outputting , by a plurality of certified, production line replaceable units, LRUs, operating in an operational environment, physical environmental data and production LRU output data; emulating , by a plurality of emulators in an emulation server, the plurality of certified production LRUs; transmitting, by the plurality of certified production LRUs, the physical environmental data and production LRU output data to the plurality of emulators via data diodes; generating and outputting , by the plurality of emulators using the physical environmental data, a model of the operational environment; generating and outputting , by a plurality of pre-certified LRUs using the model of the operational environment, pre-certified LRU output data, wherein the plurality of pre-certified LRUs correspond to the plurality of certified production LRUs; transmitting, by the plurality of pre-certified LRUs, the pre-certified LRU output data to the plurality of emulators; and allowing, by providing data diodes, only one-way transfer of data between the plurality of certified production LRUs and the plurality of emulators such that no data and/or commands can be transmitted to the plurality of certified production LRUs from the plurality of pre-certified LRUs via the plurality of emulators, wherein pre-certified LRUs are LRUs that have not been certified for use on a vehicle, and wherein each certified production LRU of the plurality of certified production LRUs is connected to its respective emulator of the plurality of emulators and each pre-certified LRU of the plurality of pre-certified LRUs is connected to its respective emulator of the plurality of emulators. <EOS>