Measuring and Modeling Relationships between Variables
Hemant Urdhwareshe, Husain A. Al-Omani, Thomas J. West · Productivity Press eBooks · 2025
In the conventional Shewhart control charts, we assume that the process output data, when it is in control, are normally and independently distributed with mean μ and standard deviation σ so that quality characteristic x t at time t is given by the following Shewhart process model: