In this research, the main parameters of the multivariate CUSUM control chart (the reference value k , the control limit H , the sample size n , and the sampling interval h ) are determined by minimizing the Lorenzen-Vance cost function (Lorenzen TJ, Vance LC. The economic design of control charts: A unified approach. Technometrics 28: 3-10, 1986 [1],) in which the external costs of employing t...

The control limits of an exponentially weighted moving average (EWMA) control chart should vary with time, approaching asymptotic limits as time increases. However, previous analytic analyses of EWMA charts consider only asymptotic control limits. In this article, the run length properties of EWMAs with time-varying control limits are approximated using nonhomogeneous Markov chains. Comparing t...

Process monitoring of multivariate quality attributes is important in many industrial applications, in which rich historical data are often available thanks to modern sensing technologies. While multivariate statistical process control (SPC) has been receiving increasing attention, existing methods are often inadequate as they either cannot deliver satisfactory detection performance or cannot c...

The aim of the study was to evaluate the single-surgeon learning curve (SSLC) in laparoscopic liver surgery over an 11-year period with risk-adjusted (RA) cumulative sum control chart analysis.Laparoscopic liver resection (LLR) is a challenging and highly demanding procedure. No specific data are available for defining the feasibility and reproducibility of the SSLC regarding a consistent and c...