Nonconfonning parts are often produced when a process moves from one level to another due to transition events. Control charting, when applied to a stable state process, is an effective monitoring tool to continuously check for process shifts or upsets. However, the presence of transition events can impede the nonnal perfonnance of traditional control chart with increased false alarms. The pres...

Intrusion detection systems typically create large amounts of alerts, processing of which is a time consuming task for the user. This paper describes an application of exponentially weighted moving average (EWMA) control charts used to help the operator in alert processing. Depending on his objectives, some alerts are individually insignificant, but when aggregated they can provide important in...

The nonparametric (NP) control charts are famous for detecting a shift in the process parameters (location and/or dispersion) when underlying characteristic does not follow distributional assumptions. Similarly, cost of estimations is very high and ranking observational relatively simple, ranked set sampling (RSS) technique preferred over simple random (SRS) technique. On other hand, NP triple ...

A major impediment to practitioner acceptance of the economic design approach to control charts is the complicated nature of the underlying optimization problem even under standard process assumptions. The economic approach to determining the optimal control limits requires estimating the derivatives of performance curves that are typically obtained via simulation. For this gradient estimation ...

The usual practice of using a control chart to monitor a process is to take samples from the process with fixed sampling interval (FSI). In this paper, a synthetic X control chart with the variable sampling interval (VSI) feature is proposed for monitoring changes in the process mean. The VSI synthetic X chart integrates the VSI X chart and the VSI conforming run length (CRL) chart. The propose...

Purpose The purpose of this paper is to evaluate the performance a modified EWMA control chart ( γ chart), which considers data distribution and incorporate its correlation structure, simulating in-control out-of-control processes select an adequate value for smoothing parameter with these conditions. Design/methodology/approach This based on simulation approach using methodology evaluating sta...

In the previous two Chapters, we proposed fraction nonconforming nonparametric control charts to monitor process location and process variability. It is also shown that performance of proposed control charts are superior to that of the Shewhart X and sign charts. If process is running in an in-control state for a long period, it will reach in steady-state mode. In order to characterize long-ter...

A traditional approach to monitor both the location and the scale parameters of a quality characteristic is to use two separate control charts. These schemes have some difficulties in concurrent tracking and interpretation. To overcome these difficulties, some researchers have proposed schemes consisting only one chart. However, none of these schemes is designed to work with individual observat...

A manufacturing process cannot be released to production until it has been proven to be stable. Also, we cannot begin to talk about process capability until we have demonstrated stability in our process. This means that the process variation is the result of random causes only and all assignable or special causes have been removed. In complicated manufacturing processes, such as drilling proces...