Abstract: The present invention describes a device incorporating artificial intelligence and corresponding methods for recommending an optimal machinability data selection, especially with machine performance degradation. The device comprises of a first component, which feeds the system with necessary inputs. A second component, which is the main processing unit, acts as an inference engine to predict the outputs. The last component interprets the outputs, conveys the processed outputs to target location and converts them into necessary tasks. The inputs are identified as the machining operations, work piece material, machining tool type, and depth of cut. The input includes machine performance characteristics as well, that is the degradation level of the machine which interrelates with machine vibration and surface finishing. The outputs are the machining parameters, comprising of the optimal cutting speed and feed rate. The inference engine can be established with fuzzy logic, neural network or neural-fuzzy.