A system to assist an individual in developing a therapy in diabetes treatment of a patient includes a user interface control module, a simulation engine, a charting and display module. The user interface control module receives an input related to the patient and captures a current time of the simulation. The simulation engine receives the input, generates a plurality of blood glucose readings for the patient up to the current time of the simulation based on the input, and to transfers the plurality of blood glucose readings. The charting and display module receives the plurality of blood glucose readings and display the plurality of blood glucose readings. The simulation engine receives patient parameters from a patient parameter library based on a selected patient model.