Improved simple linear profiling method with application to chemical gas sensors

Abstract

In industrial applications, a functional relationship between the quality characteristics of interest is well represented by profile functions. These are often characterized by linear or nonlinear relationships that depend on the nature of the experimental study. A monitoring method based on linear profiles is known as linear profiling, which is commonly used because of its simplicity. In this article, we propose a new linear profiling method based on a homogenously weighted moving average (HWMA) chart to monitor the linear profile parameters. The HWMA chart is based on the idea of allocating a specific weight to the current estimate of the profiling parameter, and the remaining weight is circulated equally among the prior estimates. The performance of the proposed control chart was evaluated using the average run length criterion and further compared with existing charts for the monitoring of the linear profile parameter. Our simulation results revealed the superiority of the newly proposed chart in terms of its quick detection ability. An example concerning gas sensors from the chemical industry is also presented to illustrate the application of the proposed chart. 2021 John Wiley & Sons Ltd.