Traditional bottleneck diagnosis of production lines mainly relies on the designer's experience, theoretical calculation or data analysis after practical system run. There are some disadvantages of the traditional bottleneck diagnosis for production lines. Using the virtual manufacturing technologies, a novel Simulation Diagnosis methodology about the Bottleneck of Production Lines (SDBPL) has been presented. With the proposed method, an existed production line is modeled, simulated and analyzed. Its bottleneck is quickly diagnosed by some ways such as visual simulation results, cycle time, machine utilization and labor utilization. Results reveal that SDBPL can find the location of bottleneck in the practical production lines without wasting practical resource because the entire course of the diagnosis for bottleneck is implemented in virtual environment, and SDBPL is quicker than that of traditional methods as well.

Achieving workpiece high accuracy at low cost is one of the greatest challenges in the manufacturing industry. A repetitive error measurement and compensation scheme to improve the workpiece diameter accuracy for machining centres is described. The scheme entails an on-machine measurement and error compensation technology between machining processes. The workpiece diameters are measured along the workpiece length by using a fine touch sensor. The workpiece diameters in the compensation program are modified for implementation of next pass error correction. The technology is realised on a CNC turning centre. This method works well in hard machining and turned workpieces with large length-diameter ratios where the machining process induced errors are significantly greater than errors from other sources. It demonstrates that the workpiece can obtain maximum possible machining accuracy by this repetitive measurement and compensation technique.

A new system for on-machine measurement of workpieces is described. The system is based on a fine touch sensor that enables the cutting tool itself to act as a contact probe to inspect the workpiece. The proposed measurement technology combines the Q-setter with the fine touch sensor. This low cost measurement system is applied to automatic workpiece setup and improving workpiece dimensional accuracy on a CNC turning center. It is shown that using the proposed measurement system results in workpiece setting time decrease and workpiece machining accuracy improvement. The development of the onmachine measurement system makes the fine touch sensor extremely attractive for CNC machine retrofitting.

Although work has been carried out on parametric programming on CNC centres, there have been few papers which focus on error compensation. Parametric programming for error compensation is presented in this paper on the basis of a simple model of machining system deflections induced by the radial cutting force in CNC turning operations. The resulting errors are introduced as compensation values to the conventional tool movements along the programmed tool path. This can result in a complex tool path. Parametric programming is applied to handle this complexity for error compensation.