A method for ranking performance of each production well in a plurality of production wells includes sensing a production parameter value for each production well using a sensor and receiving the production parameter value for each production well using a processor. The method also includes performing two or more different calculations for each production well using the production parameter value, each calculation providing a calculated performance indicator, multiplying each calculated performance indicator by a weight factor to provide a weighted performance indicator; and summing each of the weighted performance indicators for each production well to provide a unit-less performance index value for each production well. The method further includes inputting into the processor a threshold value of the unit-less performance index and identifying any production well that has a corresponding unit-less performance index value that exceeds the unit-less performance index threshold value as an under-performing well.