Title :
Control charts and process capability
Author :
Wu, Zhang ; Tian, Yu
Author_Institution :
Sch. of Mech. & Production Eng., Nanyang Technol. Inst., Singapore
Abstract :
A new design algorithm for the X¯&S control charts is presented in this article, in which the detection power is allocated between the X¯ chart and the S chart in an optimal manner. This algorithm associates the out-of-control conditions of a process with a degraded value of the process capability ratio Cpk. Specifically, when Cpk decreases to a specified value in any possible pattern, the X¯&S control charts will give a signal within a specified time period with a predetermined confidence level. This algorithm allows the quality assurance (QA) engineers to accurately specify the performance characteristics of the control charts (i.e., the in-control and out-of-control run lengths and the associated confidence levels) and assist them to achieve the desired 6-σ solution
Keywords :
quality control; statistical process control; 6-σ solution; X¯&S control charts; confidence levels; control charts; detection power; in-control run lengths; out-of-control conditions; out-of-control run lengths; performance characteristics specification; predetermined confidence level; process capability; process capability ratio; quality assurance engineers; Algorithm design and analysis; Computer displays; Control charts; Degradation; Industrial control; Process control; Production engineering; Quality assurance; Signal processing; Size control;
Conference_Titel :
Management of Innovation and Technology, 2000. ICMIT 2000. Proceedings of the 2000 IEEE International Conference on
Print_ISBN :
0-7803-6652-2
DOI :
10.1109/ICMIT.2000.916826
