An integrated SPC approach for manufacturing processes Available to Purchase

Control charts have been widely used in the manufacturing industry as the most important statistical process control (SPC) technique. One assumption for successfully applying control charts is that the process is stable to begin with and adjustments are made only at a later point when the process is deemed to be out of control. A situation that often arises is when the process is subject to a slow trend caused by factors such as equipment deterioration, power decline during its consumption, or other reasons. For this type of situation, an integrated monitoring and adjustment approach can be considered and the relevant issues involved are discussed in this paper. This problem of implementing SPC is studied from the point of view of process management, together with the concept of engineering process control. A general approach is then formulated for monitoring processes with trend and subject to regular adjustments and a specific model for a general case with linear trend is studied in more detail.