A computing system comprising: at least one computing device having at least one controller, the at least one computing device configured to tune each gas turbine in a set of a plurality of gas turbines based upon a fuel flow parameter, wherein the at least one computing device is configured to: command each gas turbine in the set of GTs to a respective base load level, based upon a measured ambient condition for each GT; command each GT in the set of GTs to adjust a respective actual value of the fuel flow parameter of each gas turbine in the set to match a nominal value of the fuel flow pressure of the set, and subsequently measure a respective actual value of the emissions parameter for each GT in the set; and perform an adjustment to a respective operating parameter of each GT in the set of GTs based upon a difference between the respective actual value of the emissions parameter and a nominal value of the emissions parameter value at the respective measured ambient condition for each gas turbine in the set, wherein the adjustment includes adjusting an operating condition of each gas turbine in the set by a fixed fraction of a difference between a respective fuel flow value and a nominal fuel flow value, wherein the adjustment to the respective operating parameter of each gas turbine in the set aligns each gas turbine in the set onto a first line in a graphical space plotting the fuel flow parameter versus the emissions parameter, wherein the first line is orthogonal to a characteristic line in the graphical space, wherein the characteristic line is a mean characteristic line of all of the plurality of gas turbines in the set, at the respective base load level of each gas turbine in the set, plotting the fuel flow parameter versus the emissions parameter. at least one computing device having at least one controller, the at least one computing device configured to tune each gas turbine in a set of a plurality of gas turbines based upon a fuel flow parameter, wherein the at least one computing device is configured to: command each gas turbine in the set of GTs to a respective base load level, based upon a measured ambient condition for each GT; command each GT in the set of GTs to adjust a respective actual value of the fuel flow parameter of each gas turbine in the set to match a nominal value of the fuel flow pressure of the set, and subsequently measure a respective actual value of the emissions parameter for each GT in the set; and perform an adjustment to a respective operating parameter of each GT in the set of GTs based upon a difference between the respective actual value of the emissions parameter and a nominal value of the emissions parameter value at the respective measured ambient condition for each gas turbine in the set, command each gas turbine in the set of GTs to a respective base load level, based upon a measured ambient condition for each GT; command each GT in the set of GTs to adjust a respective actual value of the fuel flow parameter of each gas turbine in the set to match a nominal value of the fuel flow pressure of the set, and subsequently measure a respective actual value of the emissions parameter for each GT in the set; and perform an adjustment to a respective operating parameter of each GT in the set of GTs based upon a difference between the respective actual value of the emissions parameter and a nominal value of the emissions parameter value at the respective measured ambient condition for each gas turbine in the set, wherein the adjustment includes adjusting an operating condition of each gas turbine in the set by a fixed fraction of a difference between a respective fuel flow value and a nominal fuel flow value, wherein the adjustment to the respective operating parameter of each gas turbine in the set aligns each gas turbine in the set onto a first line in a graphical space plotting the fuel flow parameter versus the emissions parameter, wherein the first line is orthogonal to a characteristic line in the graphical space, wherein the characteristic line is a mean characteristic line of all of the plurality of gas turbines in the set, at the respective base load level of each gas turbine in the set, plotting the fuel flow parameter versus the emissions parameter.