SPC is used to monitor processes and their inputs and outputs with the aim of producing a right first time output with maximum efficiency and minimum cost.
The main aim of SPC is to reduce the variation evident within a process by monitoring it and separating it into two main types (which we will discuss in more detail shortly).
One of the major causes of variation is defects in the process itself which can lead to the production of defective outputs. The correct application of SPC will identify these defects so that they can be removed from the process. Once they have been removed, the ongoing application of SPC assists in the continual improvement of the process, which can be identified by the reducing variability of the process's outputs.