Scheme for real-time process planning under process deterioration

Abstract Conventional approaches for process planning of manufacturing operations preset fixed process means and process tolerances for all operations and permit outputs to be distributed around these fixed values, provided that the final outputs meet acceptable specifications. These approaches are inappropriate for high-value and precision manufacturing processes, especially those where a complex part may suffer from process deterioration. The problem is that in these approaches, process means and process tolerances are considered to be independent decision variables, whereby the resultant process means are equal to or close to the design targets of the blueprint dimensions. In addition, they do not consider the phenomena of process shifting or deterioration as factors of manufacturing operations, but assume that process variability is small in comparison to the quality requirements. Therefore, in this study a process optimization model is introduced that simultaneously takes process means and process tolerances into account. Furthermore, it reduces process variability and offsets process deterioration by means of sequential operation adjustment. With the scheme developed in this study built into the control system, a real-time system for integrated process control and modification for making adaptive process planning can be realized.

[1]  Geir Storvik,et al.  Simulation and Monte Carlo Methods , 2006 .

[2]  Edward Abramowich,et al.  Six Sigma for Growth: Driving Profitable Top-Line Results , 2005 .

[3]  John V. Liggett.  Dimensional Variation Management Handbook: A Guide for Quality, Design, and Manufacturing Engineers , 1992 .

[4]  E S Gadelmawla.  A novel system for automatic measurement and inspection of parallel screw threads , 2004 .

[5]  Angus Jeang,et al.  Combined parameter and tolerance design optimization with quality and cost , 2001 .

[6]  Madhan Shridhar Phadke,et al.  Quality Engineering Using Robust Design , 1989 .

[7]  Fred Spiring,et al.  Introduction to Statistical Quality Control , 2007, Technometrics.

[8]  Angus Jeang.  Tolerance chart balancing for machining process planning , 1996 .

[9]  L. F. Hauglund,et al.  Least Cost Tolerance Allocation for Mechanical Assemblies with Automated Process Selection , 1990 .

[10]  Türkay Dereli,et al.  Optimisation of process planning functions by genetic algorithms , 1999 .

[11]  John H. Sheesley,et al.  Quality Engineering in Production Systems , 1988 .

[12]  Bryan Kok Ann Ngoi,et al.  Computer-aided tolerance charting , 1994 .

[13]  S Park,et al.  Mathematical modelling of geometric tolerance propagation, considering effects of datums , 2001 .

[14]  Angus Jeang,et al.  Robust product development for multiple quality characteristics using computer experiments and an optimization technique , 2008 .

[15]  Sai Cheong Fok,et al.  Optimal process plans for manufacturing and tolerance charting , 2001 .

[16]  Nafis Ahmad,et al.  CURRENT TREND IN COMPUTER AIDED PROCESS PLANNING Authers : , 2002 .

[17]  Angus Jeang,et al.  Simultaneous process mean and process tolerance determination with asymmetrical loss function , 2006 .

[18]  François Villeneuve,et al.  Geometrical tolerancing in process planning: A tridimensional approach , 1999 .

[19]  Donald F. Eary,et al.  Process engineering for manufacturing , 1962 .