1. A method of determining a desired product corresponding to a user objective, comprising the steps of: (a) providing a first said user objective; (b) providing a first set of input data; (c) automatically generating a first workflow in response to the first user objective; (d) automatically selecting one or more software modules in response to the first workflow, the one or more software modules including a build model software module adapted for building a simulator model in response to a set of other data and a tune model software module adapted for calibrating the simulator model in response to one or more of a set of transient test data and well test data and pressure gradient data; (e) executing said one or more software modules in a processor in response to said first set of input data; and (f) determining a first said desired product in response to the executing step (e), the first said desired product including a 3D representative reservoir model.