Title :
Highly specifiable np control chart
Author :
Luo, Hua ; Zhang Wu
Author_Institution :
Nanyang Technol. Inst., Singapore
Abstract :
An algorithm is presented in this article, which gives the sample size and control limits for an np chart (3-triplet np chart with fractional limits) based on the specified values of (a) the in-control fraction nonconforming value p0, and the downward and upward shifted values p- and p.; (b) the design run lengths (RL); and (c) the corresponding confidence levels. Specifically, whenever the nonconforming process fraction is equal to one of the three specified values, the np chart will produce a signal in a predetermined run length with a predetermined confidence level. This feature makes the operating characteristics of the np chart highly specifiable and provides the quality assurance (QA) engineers with more control on the design and operation of the np charts. The new np chart is designed by seeking an optimal combination of the sample size and the fractional control limits
Keywords :
quality control; statistical process control; 3-triplet np chart; confidence levels; control limits; design run lengths; downward shifted values; fractional control limits; fractional limits; highly specifiable np control chart; in-control fraction nonconforming value; operating characteristics; predetermined confidence level; predetermined run length; quality assurance; sample size; upward shifted values; Algorithm design and analysis; Condition monitoring; Control charts; Design engineering; Manufacturing processes; Optimal control; Process control; 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.2000.916823