In statistical process monitoring, the CUSUM and EWMA control charts have received considerable attention because of their remarkable ability to detect small sustained shifts. practice, variation shifts are anticipated beforehand in many processes, so focus should be on detecting a moderate large shift. The aforementioned identify minor changes population parameters as out-of-control scenarios;...

Single-incision laparoscopic surgery is cosmetically beneficial, but technically challenging. In this study, the learning curve (LC) for single-incision laparoscopic right hemicolectomy (SILRC), incorporating complete mesocolic excision to resect right-sided colon cancer, was investigated through multidimensional techniques. Between December 2009 and May 2015, 64 patients each underwent SILRC o...

This paper presents an on-line Statistical Process Control (SPC) technique, based on a Generalized Likelihood Ratio Test (GLRT), for detecting and estimating mean shifts in autocorrelated processes that follow a normally distributed Autoregressive Integrated Moving Average (ARIMA) model. The GLRT is applied to the uncorrelated residuals of the appropriate time-series model. The performance of t...

Monitoring complex production systems is primordial to ensure management, reliability and safety as well as maintaining the desired product quality. Early detection of emergent abnormal behaviour in monitored systems allows pre-emptive action to prevent more serious consequences, to improve system operations and to reduce manufacturing and/or service costs. This study reports the design of a ne...

multivariate control charts such as hotelling`s t^ 2 and x^ 2 are commonly used for monitoring several related quality characteristics. these control charts use correlation structure that exists between quality characteristics in an attempt to improve monitoring. the purpose of this article is to discuss some issues related to the g chart proposed by levinson et al. [9] for detecting shifts in ...

We read with interest the paper by Kemp and colleagues 1 which utilises cumulative sum (CUSUM) to analyse the learning curves associated with endobronchial ultra-sound-guided transbronchial needle aspiration (EBUS-TBNA). The retrospective study from five centres demonstrated that variable learning periods are required to attain proficiency in the procedure, and a pooled sensitivity of 67.4% was...

BACKGROUND The Shipman Inquiry recommended mortality rate monitoring if it could be 'shown to be workable' in detecting a future mass murderer in general practice. AIM To examine the effectiveness of cumulative sum (CUSUM) charts, cross-sectional Shewhart charts, and exponentially-weighted, moving-average control charts in mortality monitoring at practice level. DESIGN OF STUDY Analysis of ...

OBJECTIVE To evaluate the effect of learning the laparoscopic sigmoid resection procedure on resident surgeons; establish a minimum number of cases before a resident surgeon could be expected to achieve proficiency with the procedure; and examine if an analysis could be used to measure and support the clinical evaluation of the surgeon's competence with the procedure. DESIGN Retrospective ana...