A measurement system for use in analyzing an operation of process equipment within a process, comprising: a plurality of sensors (60A-N) including at least one non-intrusive sensor disposed within the process, wherein each of the plurality of sensors (60A-N) measures a different physical process phenomenon within the process to produce a sensor measurement indicative of a physical process phenomenon, and wherein the at least one non-intrusive sensor measures the respective physical process phenomenon non-intrusively with respect to the process; and a logic module communicatively coupled to each of the plurality of sensors (60A-N) to receive the sensor measurements, the logic module including a logic engine and a model that relates measurements of the values of each of the different physical process phenomenon to a further physical process phenomenon, wherein the logic module operates on a computer processor device to determine a value of the further physical process phenomenon using the model and the sensor measurements, wherein the plurality of sensors are a valve position indicator that does not require physical contact between a positioner and a valve stem, and a vibration sensor that is used to indicate presence of steam flow through a steam trap, wherein the different physical process phenomena are valve position measured by the valve position indicator and vibration measured by the vibration sensor, which are used to estimate a fluid flow in percent through a valve or other line connected to the valve based on the model , and wherein the model is a three-dimensional model in which the fluid flow percentage is associated with each combination of vibration, in Hertz, and valve position, in percent open, sensor measurements. a plurality of sensors (60A-N) including at least one non-intrusive sensor disposed within the process, wherein each of the plurality of sensors (60A-N) measures a different physical process phenomenon within the process to produce a sensor measurement indicative of a physical process phenomenon, and wherein the at least one non-intrusive sensor measures the respective physical process phenomenon non-intrusively with respect to the process; and a logic module communicatively coupled to each of the plurality of sensors (60A-N) to receive the sensor measurements, the logic module including a logic engine and a model that relates measurements of the values of each of the different physical process phenomenon to a further physical process phenomenon, wherein the logic module operates on a computer processor device to determine a value of the further physical process phenomenon using the model and the sensor measurements, wherein the plurality of sensors are a valve position indicator that does not require physical contact between a positioner and a valve stem, and a vibration sensor that is used to indicate presence of steam flow through a steam trap, wherein the different physical process phenomena are valve position measured by the valve position indicator and vibration measured by the vibration sensor, which are used to estimate a fluid flow in percent through a valve or other line connected to the valve based on the model , and wherein the model is a three-dimensional model in which the fluid flow percentage is associated with each combination of vibration, in Hertz, and valve position, in percent open, sensor measurements. <EOS>