Abstract: The structural complexity modeling and evaluation method of non-serial manufacturing systems is brought out on the basis of considering the influences of the buffers states on the overall manufacturing systems to systematically measure the complexity of the manufacturing systems, aiming at the deficiency of the present structural complexity modeling method. The buffers states is defined through creating state transition equations of the buffers so as to analyze the influences of the buffers states on the machines in different work stations of non-serial manufacturing system, which in turn turns the original manufacturing systems into equivalent systems. The universal generating function is used to describe the performance and probability, and the manufacturing systems are divided into some parallel and serial sub-systems, followed by the solution of the systems generating functions with the parallel and serial composition operators introduced. The complexity model of non-serial manufacturing systems is established based on the entropy model of information theory from the angle of system. A non-serial machining line with four stages for cylinder heads is taken as an example to verify the effectiveness of the model and the validity of the evaluation method.

Key words: Information entropy, Manufacturing systems, Structural complexity, Universal generating function, diffusion acoustic field, focus mode, nonlinear imaging, phased-array, ultrasonic array