A system, comprising: a management server having a processor with access to executable instructions, the executable instructions are configured to, when executed by the processor, cause the management server to, acquire operating data that describes operation of a valve assembly; calculate an amplitude for stick-slip cycling (X 1) and an amplitude for setpoint cycling (X 2) from the operating data, the amplitude for stick-slip cycling (X 1) and amplitude for setpoint cycling (X 2) quantifying operation of the valve assembly; calculate a maintenance variable, wherein the maintenance variable includes a pattern coefficient that modifies a value of the amplitude for stick-slip cycling (X 1) and an amplitude for setpoint cycling (X 2); compare the maintenance variable to a threshold criteria related to the amplitude for stick-slip cycling (X 1) and the amplitude for setpoint cycling (X 2), the threshold criteria separating valve assemblies into two groups (10,20) by indicating that a particular combination of stick-slip cycling (X 1) and setpoint cycling (X 2) is indicative of cycling that occurs on the valve assembly itself as a first group or is indicative of cycling that is the result of variation in the process as a second group; wherein the executable instructions further configure the management server to calculate the maintenance variable in accordance with, M = C i X i + C i + n X i + n..., wherein M is the maintenance variable, Ci is a first pattern coefficient, Xi is the amplitude for stick-slip cycling (X 1), Ci + n is a second pattern coefficient, Xi + n is the amplitude for setpoint cycling (X 2), and n is an integer having consecutive values; select a maintenance task according to a relationship between the maintenance variable and the threshold criteria, the maintenance task related to a failure mode; and generate an output conveying the maintenance task. acquire operating data that describes operation of a valve assembly; calculate an amplitude for stick-slip cycling (X 1) and an amplitude for setpoint cycling (X 2) from the operating data, the amplitude for stick-slip cycling (X 1) and amplitude for setpoint cycling (X 2) quantifying operation of the valve assembly; calculate a maintenance variable, wherein the maintenance variable includes a pattern coefficient that modifies a value of the amplitude for stick-slip cycling (X 1) and an amplitude for setpoint cycling (X 2); compare the maintenance variable to a threshold criteria related to the amplitude for stick-slip cycling (X 1) and the amplitude for setpoint cycling (X 2), the threshold criteria separating valve assemblies into two groups (10,20) by indicating that a particular combination of stick-slip cycling (X 1) and setpoint cycling (X 2) is indicative of cycling that occurs on the valve assembly itself as a first group or is indicative of cycling that is the result of variation in the process as a second group; wherein the executable instructions further configure the management server to calculate the maintenance variable in accordance with, M = C i X i + C i + n X i + n..., wherein M is the maintenance variable, Ci is a first pattern coefficient, Xi is the amplitude for stick-slip cycling (X 1), Ci + n is a second pattern coefficient, Xi + n is the amplitude for setpoint cycling (X 2), and n is an integer having consecutive values; select a maintenance task according to a relationship between the maintenance variable and the threshold criteria, the maintenance task related to a failure mode; and generate an output conveying the maintenance task.