A computer (50, 60) configured to simulate an oil and/or gas processing facility with a configuration amongst a plurality of alternative configurations, comprising: an input interface configured to enable a user to input a limited data set including one or more of a type of the oil and/or gas processing facility, a production rate profile of the oil and/or gas processing facility and a geographic location of the oil and/or gas processing facility; a processor coupled to the input interface and configured to run a routine comprising one or more rules to: responsive to the user inputting the limited data set, automatically complement the limited data set with data from one or more of a feedstock database, a process utility specifications database and an ambient conditions database and form a detailed data set including one or more of an oil composition, a gas feed composition, a feed temperature and a feed pressure; interpret the detailed data set to determine the configuration of the oil and/or gas processing facility amongst the plurality of alternative configurations to comply with one or more desired specifications of an oil and/ or gas product; generate one or more sub-process templates, select one or more sub-process templates from one or more sub-process libraries and populate the one or more sub-process templates with the detailed data set; connect the one or more sub-process templates to create a model of the oil and/or gas processing facility, the model requiring input beyond the limited data set; and execute the model and calculate a mass and energy balance to find a stable operating point for the oil and/or gas processing facility; and an output interface coupled to the processor configured to output results produced by the model to a display monitor, a file, or a combination thereof. an input interface configured to enable a user to input a limited data set including one or more of a type of the oil and/or gas processing facility, a production rate profile of the oil and/or gas processing facility and a geographic location of the oil and/or gas processing facility; a processor coupled to the input interface and configured to run a routine comprising one or more rules to: responsive to the user inputting the limited data set, automatically complement the limited data set with data from one or more of a feedstock database, a process utility specifications database and an ambient conditions database and form a detailed data set including one or more of an oil composition, a gas feed composition, a feed temperature and a feed pressure; interpret the detailed data set to determine the configuration of the oil and/or gas processing facility amongst the plurality of alternative configurations to comply with one or more desired specifications of an oil and/ or gas product; generate one or more sub-process templates, select one or more sub-process templates from one or more sub-process libraries and populate the one or more sub-process templates with the detailed data set; connect the one or more sub-process templates to create a model of the oil and/or gas processing facility, the model requiring input beyond the limited data set; and execute the model and calculate a mass and energy balance to find a stable operating point for the oil and/or gas processing facility; and responsive to the user inputting the limited data set, automatically complement the limited data set with data from one or more of a feedstock database, a process utility specifications database and an ambient conditions database and form a detailed data set including one or more of an oil composition, a gas feed composition, a feed temperature and a feed pressure; interpret the detailed data set to determine the configuration of the oil and/or gas processing facility amongst the plurality of alternative configurations to comply with one or more desired specifications of an oil and/ or gas product; generate one or more sub-process templates, select one or more sub-process templates from one or more sub-process libraries and populate the one or more sub-process templates with the detailed data set; connect the one or more sub-process templates to create a model of the oil and/or gas processing facility, the model requiring input beyond the limited data set; and execute the model and calculate a mass and energy balance to find a stable operating point for the oil and/or gas processing facility; and an output interface coupled to the processor configured to output results produced by the model to a display monitor, a file, or a combination thereof.