  In this article an SPC case study is presented. It consists of monitoring a
manufacturing process used for different products of similar kind. So far, each
of these products is monitored individually. However, if there is e.g. a
quality problem with one joint component, this signal will be distributed over
different control charts. Therefor a standardization is introduced, similar to
short run SPC methods. Then control chart methods are applied to detect process
deviations. If there are observations out of control, a next step is taken and
process information are analysed in order to derive possible root causes.
