A diagnostic method for a weighing scale having multiple force measuring devices, comprising: selecting a plurality of like weighing scale components to be monitored; selecting as a diagnostic parameter an operating parameter (30, 65, 100, 135) that is common to the selected like weighing scale components and should have approximately the same value for each component during normal operation; receiving at a computer device from each of the selected weighing scale components, an output signal representative of the selected diagnostic parameter (40, 75, 110); characterized by determining the outlier weighing scale component by operating calculations at the computer device comprising the steps of: at the computer device, applying a standard statistical test to the received diagnostic parameter output signal values received from the selected weighing scale components; at the computer device, determining if the results of the statistical tests indicate that the diagnostic parameter output signal value of any weighing scale component is a statistical outlier compared to the diagnostic parameter output signal values of the other weighing scale components; and if the diagnostic parameter output signal value of a given weighing scale component is statistically determined by the computer device to be an outlier, using the computer device to indicate a problem, wherein the standard statistical test is Chauvenet's criterion, Grubbs' Test for Outliers, Peirce's Criterion or Dixon's Q Test. selecting a plurality of like weighing scale components to be monitored; selecting as a diagnostic parameter an operating parameter (30, 65, 100, 135) that is common to the selected like weighing scale components and should have approximately the same value for each component during normal operation; receiving at a computer device from each of the selected weighing scale components, an output signal representative of the selected diagnostic parameter (40, 75, 110); characterized by determining the outlier weighing scale component by operating calculations at the computer device comprising the steps of: at the computer device, applying a standard statistical test to the received diagnostic parameter output signal values received from the selected weighing scale components; at the computer device, determining if the results of the statistical tests indicate that the diagnostic parameter output signal value of any weighing scale component is a statistical outlier compared to the diagnostic parameter output signal values of the other weighing scale components; and if the diagnostic parameter output signal value of a given weighing scale component is statistically determined by the computer device to be an outlier, using the computer device to indicate a problem, wherein at the computer device, applying a standard statistical test to the received diagnostic parameter output signal values received from the selected weighing scale components; at the computer device, determining if the results of the statistical tests indicate that the diagnostic parameter output signal value of any weighing scale component is a statistical outlier compared to the diagnostic parameter output signal values of the other weighing scale components; and if the diagnostic parameter output signal value of a given weighing scale component is statistically determined by the computer device to be an outlier, using the computer device to indicate a problem, wherein the standard statistical test is Chauvenet's criterion, Grubbs' Test for Outliers, Peirce's Criterion or Dixon's Q Test.