1. A method, comprising: obtaining user inputs, process inputs, and first process outputs of a first process control system connected to first field devices; providing the user inputs and the process inputs to a second process control system not connected to the first field devices and not connected to any other field devices, the user inputs and the process inputs to test the second process control system; obtaining second process outputs of the second process control system operated with the user inputs and the process inputs; and comparing, using a processor, the first and second process outputs to determine whether the second process control system is implemented as intended.