The "Volumetric Flow" model is the default model if you create a new project, can be used for either Oil or Gas projects, and is the most commonly used calculation method. This model tracks up to 17 products and gas components and optimizes hydrocarbon throughput in a Flow Network of wells and facilities that are connected through pipelines with definitions of allowed product types and maximum flow rate.

Volumetric throughput constraints, such as maximum fluid handling, maximum gas capacity, maximum steam rate or maximum H2S content,  can be defined at the wells and facilities. Production forecasts are defined at the wells with Decline Analysis, Product Ratios or Production arrays (imported forecasts) and are tracked on a Rate-Cum basis so that reserves remain consistent when production curtailment is required to honor the capacity limitations in the Flow Network.

The "Pressure Flow" model is for more detailed gas gathering system modeling. The pressure model uses AOF/Test data along with Reservoir pressure and pipeline dimension data to flow the gas through a nodal pressure analysis. This allows for integrated analysis of production and economic factors when modeling such things as forecasting gas compression requirements and pressure backout in gas fields. Although water and gas byproducts are calculated in this model, the pressure loss model is limited to dry gas pressure loss correlations.