A CUSUM chart for detecting the intensity ratio of negative events

Abstract

This paper developed a single cumulative sum (CUSUM) scheme, called the UCUSUM chart, for simultaneously detecting the size N and time interval T of an event. The new chart used the information of size and frequency of the event and the UCUSUM chart is carried out using the only one statistic U, which contains both T and N; on the other hand, the UCUSUM chart could allocate the detection power to the T shifts and the N shifts. The results present that the UCUSUM chart is significantly powerful compared to other charts which are in the current research with either the time interval T or with the size N. The UCUSUM chart could be applied in many areas including industries and non-industries and the performance of the new chart shows it is much effective in example.

Keywords:

• statistical process control
• time between events
• frequency and size
• CUSUM chart
• ratio of negative event

Disclosure statement

No potential conflict of interest was reported by the authors.

Acknowledgements

The authors would like to thank the editor and the anonymous referees for their helpful and valuable comments and suggestions that have improved this article significantly.

Additional information

Funding

This work was supported by National Natural Science Foundation of China [grant number 71402118], [grant number 71532008], [grant number 71672122].