An electrosurgical system includes an energy source adapted to supply energy to tissue. The energy source includes a microprocessor configured to execute a tissue treatment algorithm configured to control the supply of electrosurgical energy to tissue and process a configuration file including at least one parameter of the tissue treatment algorithm. The at least one parameter is adjustable to effect a tissue seal result. The microprocessor generates a target impedance trajectory based on at least one parameter of the tissue treatment algorithm and is further configured to drive tissue impedance along the target impedance trajectory by adjusting the supply of energy to tissue to substantially match tissue impedance to a corresponding target impedance value. The system also includes an electrosurgical instrument including at least one active electrode adapted to apply electrosurgical energy to tissue.