International Journal of
Physical Sciences

  • Abbreviation: Int. J. Phys. Sci.
  • Language: English
  • ISSN: 1992-1950
  • DOI: 10.5897/IJPS
  • Start Year: 2006
  • Published Articles: 2557

Full Length Research Paper

Hi-tech manufacturing process selection problem for very low fraction of defectives with multiple characteristics

Feng-Tsung Cheng1, Mei-Fang Wu1* and W. L. Pearn2        
1Department of Industrial Engineering and Systems Management, Feng Chia University, Taiwan. 2Department of Industrial Engineering and Management, National Chiao Tung University, Taiwan.
Email: [email protected]

  •  Accepted: 20 June 2011
  •  Published: 23 September 2011


Hi-tech manufacturing process selection is the problem of comparing two processes and selecting the one that has a very low fraction of defectives (VLFD). In this paper, we consider process selection by , which is an extension of the widely-used popular indexCpk to cases with multiple characteristics. We propose an analytical approach is proposed to tackle the process selection problem. Hypothesis testing using two procedures to compare the two processes is developed. Critical values of the test are obtained to determine the selection decisions. Sample sizes required for designated selection power and confidence levels are analyzed. The results provide useful information to practitioners. We present an applied example that compares two light emitting diode (LED) production processes to illustrate the practicality of the proposed approach to a real problem in a factory.


Key words: Manufacturing process selection, production yield, process capability index, non-conformities, very low fraction of defectives.